The ideal greenhouse temperature ranges between 64 and 75 ºF, depending on the type of plant being grown. Maintaining an optimal relative humidity level of around 80 is crucial for optimal growth and plant health. Most plants thrive with humidity levels between 50 and 80 percent, but the ideal humidity is often around 80 percent. Humidity affects transpiration rate and nutrient levels, and good management of these factors is essential for optimal greenhouse cultivation.
The recommended humidity level for optimal plant growth in a greenhouse is 80 percent, as too much humidity can significantly reduce yield. The optimal relative humidity level for most plants is around 80 (usually 65-75 during the night and around 80 in the day). If the humidity level increases or drops, your plant’s physiological state may be affected.
Planting your greenhouse planting schedule according to day length, managing plant locations based on temperature, and choosing the right crops are essential for maintaining the perfect environment. Essential greenhouse accessories help regulate temperature and humidity, making it easier to maintain the perfect greenhouse environment.
Most plants thrive at temperatures between 18°C and 24°C, with relative humidity between 40 and 80. The ideal temperature for a greenhouse is between 25-28 degrees Celsius, but with fluctuating UK temperatures, the ideal temperature for a greenhouse during the day is typically between 70°F and 80°F to foster plant growth.
📹 When + When NOT to Use a Heat Mat and Humidity Dome For Seed Starting
Heat mats and humidity domes can be a beneficial resource for seed starting, but there are specific times to use them and when …
What is the minimum temperature for a greenhouse?
Tropical houseplants are particularly vulnerable to cold, needing at least 55°F for survival. Prolonged freezing can be fatal for some plant species. Overwintering plants in an unheated greenhouse creates a refuge for beneficial insects. Plant hardiness varies, and root hardiness is nature’s way of preserving life underground. While not ideal for delicate plant species, an unheated greenhouse offers a protective barrier, allowing gardeners in colder climates to grow longer.
To keep plants alive and thriving in a greenhouse during colder weather, group similar plants and select the right crops. These tips help keep plants in great shape during the cold weather all winter long.
What is the ideal temperature and humidity for indoor plants?
Most plants thrive in a humidity of 60 or more, with cacti and succulents averaging around 40. However, higher humidity levels can be uncomfortable for humans. A 50-60 humidity range is ideal for plants, as it helps them adapt to hotter temperatures and a more humid environment. Plants, like tropical and rainforest-originating houseplants, prefer humidity, which is essential for their growth. To create a micro-environment that reflects warm summer nights, aim for a humidity range of 50-60%. This will help plants adapt to the hotter temperatures and create a comfortable environment for all.
What should the humidity be in a greenhouse for plants?
The optimal relative humidity for most plants is around 80, which is ideal for greenhouse plants. Higher humidity levels can slow down plant physiological processes, leading to slower growth and lower quality output. High humidity levels also increase susceptibility to humidity diseases like botrytis or powdery mildew. Growers should understand, control, and maintain humidity to suit their target crops, rather than attempting to reduce it.
Is 70% humidity too high for plants?
Indoor humidity is crucial for human health and comfort, with the Mayo Clinic recommending a range of 30-50 degrees. Plants, however, require a humidity level of 70-80 degrees. Plants absorb water through their roots, which is then released through transpiration. High temperatures, sunlight, drafts, or low humidity can cause rapid water loss, making it difficult for plants to maintain good hydration levels. Low humidity can result in drying and browning around leaf edges or tips, similar to marginal leaf scorch in outdoor trees.
To address this issue, plants should be selected based on their need for high humidity, such as ferns, Rex begonias, Prayer Plant, and Calathea spp., while plants that tolerate low humidity include cacti, succulents, cast iron plants, Chinese evergreens, Devil’s Ivy, Philodendrons, and Draceanas. Selecting plants based on their humidity requirements can help ensure their growth and health.
What is too hot for seedlings in greenhouse?
Ideally, the ideal temperature for a DIY greenhouse is 80-85°F (26-29°C) during spring and summer. Anything above 90°F is alarming. It’s recommended to monitor greenhouse temperatures with a thermometer. Polycarbonate greenhouses are designed to keep the growing space warm and cozy, but managing the heat during summer can be challenging. There are ways to lower temperatures, upgrade your DIY backyard greenhouse, and ensure plants thrive during the sunniest months. There are numerous ways to improve your greenhouse kit and ensure your plants thrive during the hottest months.
At what temperature should a greenhouse vent open?
The roof vent is the most crucial outlet in a greenhouse, as it allows hot air to rise and has the strongest effect in warm and stuffy conditions. Roof vents should open to about 55 degrees, and there are two main types of side vents: hinged and louvred. Louvred vents allow air to enter through angled slats, which can be elegant and artistic, but are generally less effective. Side vents should be situated down low for good air circulation, with cooler air replacing hot air.
During winter, it is essential to maintain ventilation to prevent stagnant and overly humid air, which can lead to mold and plant disease. Open vents by about an inch or two for a couple of hours in the middle of the day, but avoid doing so during windy or very cold conditions. The importance of ventilation increases if using a heater.
Automated ventilation is not as complex or expensive as it may seem, as it can work with simple tubes with a heat-expanding element. Auto vent openers can work with simple tubes or solar-powered ones. Manual ventilation puts pressure on the grower to be on the ball when it comes to temperatures and crop care, making it worth considering automated options.
What temperature should initial vent be?
The ideal air temperature from a properly running air conditioner depends on the specific temperature coming out of the vent. If the AC system is operating correctly, the air coming out should be about twenty degrees cooler than the regular temperature inside. For example, if the house is 80 degrees and the air conditioner is cooling, the ideal temperature should be about 60 degrees. If you have more air conditioner questions, you can ask them in the comments or on Facebook or Twitter. Ingrams is a trademark of Ingrams Water and Air.
What is the optimum humidity for seedlings?
After germinating seeds, maintain a temperature of 70-80 degrees during the day and 60-65 degrees at night for optimal growth. This temperature allows plants to maintain high photosynthesis for food production, while reducing the night temperature ensures steady growth for strong, compact plants. Maintaining a minimum of 35 percent relative humidity is crucial, with the optimum around 60 percent. Place trays and pots on pebbles in standing water for optimal humidity.
Air circulation is essential for good plant growth, and running a room fan can help increase carbon dioxide availability and reduce disease incidence. Seedlings are ready for transplantation when they have grown their first set of true leaves, which appear two to four weeks after germination.
What is the ideal temperature and humidity for plant growth?
Plant growth is influenced by three main temperature points: minimal, optimal, and maximum. The vegetative phase requires 25 degrees Celsius and 60-70 humidity, while the flowering phase requires 28 degrees Celsius and 40-50 humidity. Maintaining these temperatures is crucial for optimal photosynthesis and overall crop development. To optimize growth, consider factors like light, CO2 levels, water, temperature, and nutrition. Humidity, the amount of water vapor in the air, is also important.
Reduced humidity can cause water loss from plant tissues, while high humidity can lead to the development of microbial and fungal pathogens. Keeping these factors in mind can maximize plant growth and yield.
What is the best temperature for plants in a greenhouse?
A greenhouse is a perfect environment for growing crops, as it requires controlled temperature and humidity. The ideal temperature ranges between 64 and 75 ºF, depending on the plant, and an optimal relative humidity level of around 80. Growing all your favorite fruits and vegetables all year round is impossible outside due to temperature changes, but inside a greenhouse, you can maintain moisture, warmth, and light for optimal growth. This allows you to buffer ambient temperature and control humidity levels.
When can I put plants in an unheated greenhouse?
Seedlings can germinate in an unheated greenhouse during colder months, such as late winter to early spring. They can be placed in their seed starting trays or pots when they are still tiny, and can be transplanted when they have just two sets of leaves upwards, usually 2-4 weeks old. The ideal temperature for starting seedlings in an unheated greenhouse is around 18 degrees Celsius or 65 Fahrenheit, with a nighttime temperature of around 10 degrees Celsius or 50 Fahrenheit. Too much temperature drop can hinder seedling development, and anything over 24 degrees Celsius or 75 Fahrenheit is considered too warm.
📹 BuildASoil: WHAT IS THE IDEAL TEMP AND HUMIDITY FOR VEG?(Season 4, FAQ 5)
FAQ 5, Season 4: This is a frequently asked questions video where we answer your grow questions directly from the comments …
What I learned today: 1) warm weather crops prefer the heat mat and cold weather crops do not want it. 2) Don’t wait until all seeds have sprouted before removing the humidity dome. Remove the dome after I see my first sprouts, otherwise I risk legginess in the stems and gray mold. ( and I have had both when growing microgreens) Thanks! 😃
Just sharing my tip. Clear plastic egg containers work really well for me. Each egg cell can be a different plant, you just need to map it on paper. Keep the top, that is your dome. After sprouting, you can spoon out the seedling for transplanting into a room temp pot without disturbing the roots. Of course this won’t work with large seedlings like squash, but it is perfect for herb seeds and peppers. Depending on your mat, you may need to have a towel or 2 between the mat and egg crate. Always use boiling water to wet your soil mix, this will kill fungus gnats and mold spores. Let it cool sufficiently before you plant. I will get algae growing in cells if it is left too long, but no mold or gnats.
I am learning so much!!!! I bought heat mats last year. Yes I used them after germination and yeah the plants were a failure, but now I understand why!! I also learned fr your viewers to use the heat mats to help my sourdough stater get going. My house is usually 65-68 degrees. I have a heck of a time. So much great information!!! ❤❤❤❤
Second year grower and yeah I left the mat and humidity domes on too long. Also had the green mold on top of the soil from too much moisture, every rookie mistake made. I know that improper lighting technique can cause legginess but I wonder if too long on the mat also contributed to the lengthy gams I ended up with. Not a total seed-starting failure but lost quite a few by not being more careful. Just starting up again in the PNW, thanks for the timely tips Luke.
Thanks for you article! My husband & I conflict on when to use a humidity dome. But then I do use Heat mats right now with some of my seedlings on cold nights because I am growing in my Unheated Greenhouse. So only on the cold nights and then 1st thing in the morning at 5:30am I turn them off and check if I need to water them Also my Heat Mats only heat up to 10 degrees above the ombieny temperature, so I hope that is OK. Thanks again for all your articles. I have been following you for years.
I definitely like my heat mat and humidity domes. My seed starting took off once I added in the heat mat. My peppers (especially), watermelons, squashes, etc. definitely have to have it, my tomatoes and a few other summer veggies like it pretty well. I use the dome for most things, but not peppers, because they don’t like “wet feet”. Plus my grow table is in a pretty dry spot of our little house. Great info Luke as always!
Question: I live in Colorado…dry climate. I grow microgreens on coconut coir mats in a cheap mini-greenhouse in my family room. In the past I’ve used heat mats until the seeds sprout, have grow lights on each shelf, and have a small desk fan blowing over 12 hours a day. My question is: I’ve never grown broccoli microgreens/baby greens, so will they benefit from a cooler environment since they are a cooler weather crop? Ty for your VERY informative articles. Even at 67 years old, I’m learning lots from them!
Thank you Luke. I started my brassicas indoors and did exactly the opposite of what you said to do. This is my first time starting indoors and I’m a rookie, so you were absolutely right. I’ve got a ton of leggy cabbage, bok choy and broccoli. Oh well, I’m going to get them in the ground on Monday because we will be past a frost tonight and tomorrow. I hope they make it until Monday! Thanks again for your great teaching. (And your seeds!)
i’m so glad I came across this article. I’m just starting to grow my own seeds for the first time. I bought a humidity dome. I just started seeing kale and lettuce and put the dome on even though they sprouted two days ago. I probably should not have planted peppers in the same cells because I now understand they need help with heating mat, while lettuce and kale will not. UGH. Anyway, great article and now I will not be using dome since seeds have sprouted. Thank you!
If I may, two questions. My seeds are started on a wire shelving unit. Should I line the shelves with foil under the heat mat and the trays holding the cells? And how do you label the cells when using a humidity dome? My labels don’t fit under the lid and I water from the bottom and they move. I buy your seeds almost exclusively and I’m going to start your trifecta+ on our homestead gardens. Thanks Luke!
Basic household temperatures in the winter are recommended to be 68° in winter. If you have been outside where it is32° it is not only going to feel much warmer than outside that difference of 7° between 68° and 75° will save you 14-21% on your heating costs. Additionally, having indoor temperature of 72 and higher is a great incubation temperature for viruses and bacterias trapped indoors meaning you and your family will be more susceptible to becoming sick in the winter. And then there are those sicko people like myself who prefer the temp between 55°-60° who do need the heat mats for most germination although I think I have been misusing the domes. Love all the info.
Oh man! This is what I was searching for when I started my seeds. I couldn’t find this info anywhere and so I just did the wrong thing 😂 I didn’t use a heat mat but I totally used the dome WAY too long. So far everything is still alive but I’m afraid I will start seeing them die off. Hopefully I didn’t damage them too badly!
Considering the on and off weather in my region, I thought I was playing it safe with having the seeding mat set up in my basement. But thanks to this article, I might be able to save my seedlings before it’s too late. I’m using the cheaper mats (which ran for 20 bucks so I can’t be too mad there) which have no dial/settings. They work well!.. too well. And without domes on my current trays I had no way to control humidity outside of watering them heavily. Welp, hopefully these seeds germinate before I have to spend more dosh on trays. Thanks again for being super knowledgeable Mlgardener! I’ve been gardening for years, but even some of the simple methods can be a bit of a challenge to tackle.
Thank you so much. I really needed this article. Last year I had a lot of difficulty with germination rate, so I picked up a heat mat/thermostat kit and humidity dome, and this year it was like magic. Everything sprouted quickly. But I also got white mold and now I know I need to put that stuff away quickly after sprouting.
When would you recommend taking your seeds off the heat mat in the case that only a couple have sprouted? I have parsley currently germinating and only 3 have fully sprouted but planted 20+ seeds. Would you recommend just taking them off the heat mat now that sprouting has begun and let the other seeds germinate slower without the extra heat?
Perfect timing, as usual. We are starting seeds here, too. I have killed sprouts with the heat mat as well as the humidity dome. Both were due to me using them for too long. The heat mat completely dried out my soil overnight. The dome has caused dampening off and mold issues. Now I only use them in winter, only in conjunction with each other, and only until the first seeds sprout. Funny that I spent at least a couple of hours yesterday researching when to remove the dome, lol. Second year gardening and I’m still learning some of the basics. Also, the MIgardener cover crop is working great over wintering my raised bed. So nice to see it full of life instead of just sitting there fallow.
Thanks for the article! A quick question. I’m aiming to grow watermelon using a propagator + grow light + heat mat in middle of August. After the seeds have germinated and seedling are ready, I will transplant them in pots inside a greenhouse. Both propagator and greenhouse in inside my conservatory room. My question is that will I be harvesting watermelon sometime say around November or December. As I reckon that is the whole point in controlling all the parameters in order to have our desire vegetables and fruits out of their usual season. I’d appreciate you your response. Best.
I use those carry out containers to start plants, too. Those large trays haven’t worked well for me. I got the idea from Growing a Greener World, Craig, the tomato expert, who starts many seeds in small trays and moves them to 3 inch pots. His name is Craig, so why wouldn’t I listen? There is one container I liked but could not use, and that is the rotisserie chicken container from Costco. Even though it seemed like a mini greenhouse, plants did not grow in it. I don’t know why, but it’s back to the recycling bin. There is one more thing I figured out. When moving from the start container to the 3″ pots, I use a small plastic fork to carefully dig the seedlings, which avoids root damage and I use a plastic spoon to press the soil evenly around each transplant. I get the best seed growth this way using heat pads, and when the first ones sprout, I turn off the pads, and they keep on growing and sprouting. Thanks again, Luke, and may the Lord bless you and yours.
I have domes that are a lot taller, about 12-16 inches above the container and they have vents. Can I keep them on longer once the plants start to grow if the vents are open all the way? My cat likes to eat my seedlings and I grow in my basement where there is a wood stove. Thanks for all your great advice. I buy seeds every year and have great success!!
Hey Luke I read about a lab made hybrid called rabbage, a cross between a cabbage and a crazy as it sounds a radish. The article said they were really delicious, I think you ate the leaves. But the article said as they disappear from gardens they may never be found in the near future. I would love to grow some to see if they are worth saving. But I can’t find any seeds. Please help me!
Most everything i see says to prop up the dome until most have germinated, which i have always done. Often for several days, especially for peppers, because they tend to germinate randomly. This year i will try taking the dome and heat mat off earlier than i normally do. And maybe turn the heat mat lower for my peppers and tomatoes. I typically have the thermostat set 82 for those and they pop up in like 4 or 5 days. Maybe i will set them more at 77, 78?
I used a humidity dome in the hottest part of the summer. Planted 10 seeds per cell 4 sets of 36 cells like 2,000 lavender seeds all sprouted leggy none survived. I think it was so hot it was so wet/ hydrophobic. Should have sprouted them inside and moved them outside once or twice per week and late late in the season. I had good luck in the flower box over wintering them and covering with soil.
Good evening. Another useful article, as always. I live in the Caribbean so desirable temperatures for germination of seeds is never an issue. However, I do find that the soil in my seedling trays dries out really fast and I have a hard time getting surface sown seeds (carrots for example) to germinate. Would a humidity dome be useful in cases like these?
Hi there! What should I do if I the different seeds I am growing all require different germination temperatures? For example, I am starting tomato seedlings, which require 86° soil temps, and I am also starting lettuce seedlings, which require 68° soil temps, all in the same seed tray. I am not sure what to do. I am growing on a small scale (two 24-cell trays, 48 cells in total) for my home garden.
If I start seeds (cracked with tiny tail) in water/paper towel (anything that precedes the dirt & tray) and then put them in the dirt & tray am I still in that part where I apply heat & dome or do I skip the heat part entirely (it’s germinated) and just keep the dome until they break the surface? These are questions that have me up at night
I have never used a heat mat. Growing in a large shed i think the day time early spring heat would kill the seedlings if i did. The light heats up the soil and plants more than enough. I use a dome until they outgrow it but the dome vents are always open never closed. Most days i will take dome off and let a fan blow on seedlings for 4 hours or so. I don’t lose any seedlings with this method.
Any thoughts on these seed starter kits that have an individual led on each growing cell? So far so good but im not sure if these little lights are powerful enough.. almost doesn’t seem necessary if im going to be putting them by a big picture window once they sprout still deciding if I should just get a t5 or just leave them in the window…
I think they could be good at the beginning or end of season to extend or double the seasons just have control but only in moderation. Maybe sprout them early inside with that stuff and let them harden inside and move them outside let them harden outside on a good early day and switch it out between inside with and without it and outside with and without it
My biggest issue with starting seeds indoors is that my house is unnaturally cold during the winter. It’s very old and poorly insulated so on very cold days my house’s internal temperature is anywhere between 45 to 55 degrees. I bought a heat mat to try this year but I am still trying to figure out how to keep the plants warm overall once they germinate. I’ve seen a lot of conflicting advice so it’s getting a bit frustrating. I have several varieties of tomatoes that I want to grow that I cannot find starts for, so I have to start them from seed myself. Last year, without a mat, they didn’t germinate at all so I had to go without. And the ones that did germinate ended up having fungal issues and dying before it got warm enough to plant outside. Any advice on how to best (cheaply) keep them warm overall?
I need a heat mat to start literally any seeds. Because of my cats, i have to start all my seeds down in my concrete cold basement. It’s like 50 degrees down there. Once i get the seeds to germinate, the grow lights seem to be enough to keep them going. But with no heat mat, I’ll be waiting until April for my seedlings to pop up. Even if I plant them in January.
I like a heat mat for seed germination. once I see the sprout..the heat mat is unplugged, sanitized, and put away till next time.. Its worth it to purchase a quality heat mat with temperature control, and a soil thermometer..soil will hold heat..so the soil temp, and heat mat temp may not be the same..
I been growing lettuce and onions outside all winter.. Don’t need a heat mat! For my peppers, Yes use a heat mat!!! Another thing to look at is the overnight low temps. Cucumbers need it to stay above 55 at night, or they refuse to grow, and may even die! Do a little research on the plants you grow, and your garden will thank you…
I take a lot of cuttings so I use domes for months on the same plants sometimes if it’s something that takes a long time, but I just scrape off the top layer and replace it with fresh dry soil every time they look like they need it and it works wonders. I stopped using cinnamon on algae ages ago. You don’t really get anything besides algae growing if you keep the vents open and just use plain potting mix I find, but as soon as you add any organic amendments you get grey mould like you’re saying. I only use liquid feedings in domes if anything needs it. Never happens with that.
I am 20 min from New York City in New Jersey. I have ALWAYS had difficulty transplanting lettuce outside 😭. Should I transplant outside as soon as they germinate? At this point, I’m thinking of just waiting until mid to late April and direct seeding outside. ANY help you can give me would be appreciated. Thanks. 😁
I wish I would have seen this article two weeks ago. I’m trying to grow tomatoes and peppers from seeds for the first time. So I got a grow light and a heat mat. I jus assumed the heat mat was programmed to only heat to the proper temperature. it’s been 12 days since I sowed 60 seeds between the 2 types of plants. I have 6 seedlings. Nothing else germinated. So out of curiosity, I threw a thermometer inside my humidity dome. Ya, those poor seeds have been sitting about 88 to 90 degrees Fahrenheit. So I bought a thermostat for the heat mat, and guess I’m going to be restarting new seeds
Here in Britain at least, heat mats are an absolute necessity for cucumbers, squash etc.. Even inside, it simply isn’t warm enough to get good germination (i.e. consistently above ~70F) until way too late in the season, unless you want to spend a fortune leaving the space heating on, way too high, all day. Also, some wood burners now have air intakes that draw from outside the house. They don’t draw air from inside the house, which is what causes the low humidity, by drawing cold air into the house to replace the burnt air, and heating this new air, causing its relative humidity to decrease.
A heat mat will raise the temperature around 15-20 degrees. And that’s a bit to inconsistent for me. This is why I use a controller with a temperature probe alongside my heating mat. They’re relatively cheap and super easy to use. The mat plugs into the controller and you adjust the settings to the preferred temperature. And with the humidity dome,it can cause the plants that are sprouted to stunt. Too much humidity and the leaves can’t transpire,and if they can’t do that they can’t take up nutrients and thrive.
My 15.00$ heat mat will arrive in 2 days from Amazon so this article is perfect right now. Here in da UP 5b not only is my grow room either heated with a wood stove or a portable radiator and both can carefully be used for my warm weather plants however, I am planning on getting chicks in the spring. This winter has been freaky warm with 2 days below 0 so far and in the 30’s melting mid February. So starting my brassicas and alliums early is perfect. This year’s goals are onions, napa, and ‘swedes’ growing to perfection. That means w/o infestation, and bolting and to fruition. So why buy a heat mat? Hubby’s building me a portable backyard chicken ‘tractor’. I hope to start growing sustainable duo purpose American Bresse. Eggs are over 4.00. Nuff said. Habd
Luke, I noticed you made this article with your knee on the floor . You can raise the legs on your table and buy a stool to adjust to the appropriate height so you can comfortably sit when you start seeds in articles. Twenty years from now your knees and back will thank you. Gardeners should consider incorporating ergonomics practices while you are still limber. I thought you made a article on this somewhat recently👨🔧❤🩹🍈
Ok, interesting, but way too many things. Could you make a few articles for a beginner on one specific plant type? In my case, I have tomatoes and peppers; onions and lettuce; deer/rabbit repellant “Marigolds”. (or maybe a web page for each type that points to a specific timestamp of a article.) One thing I have not seen is how many seeds should I plant if I want so many plants.
I love your seed shop online. I’ve got seeds from there for a couple of years. Have you noticed all of your articles are about mistakes? I think it’s very negative. Maybe you’re tuning in to a beginner gardener audience. But for us who have learned over the years, what works best. We would benefit from more experienced tuned information.
If you have separate domes (which are available) in most small pot sizes then you can remove the domes individually as the seedlings emerge. Also if you germinated in Rockwool minis or Jiffy Coco Pellets then you could remove each plant from the propagator as they emerged too.. What I’m trying to say is your method is not what professional growers do and it’s not the equipment they would use. 90% of food is grown in Rockwool in NFT or SLAB Hydro methods., They also grow from cuttings all the time. The seeds are just for finding the mother plants to keep and take clones from.
I dont understand why Im having failures in germination. Ive started seeds for decades and never had jush problems. I wash the cels & trays in light bleach water every spring. I seed in feb-mar in seed starting medium. I used to use tegular potting soil. I even failed starting zucchini. Around here Zukes are almost a nuisance plant. But I failed starting them. Only in the last 3 years. I dont use heat mats. I bought them, but dont use them since I went solar.
45 degrees for lettuce germination, wow that’s super hot! . . . Ohhhh you mean 7 degrees not 45 degrees, now I understand! I would never germinate lettuce seeds at 117 ish degrees Fahrenheit. Fahrenheit is almost exclusively an American thing; translations to normal temperatures (ie Celcius) would be appreciated.
I don’t know why this kind of bad information about heat mats continues to be spread. If you want a jump start on growing seedlings early in the season, use a heat mat, but always with a thermostat set at around 75F or 24C. This will keep the soil at a constant temperature and stop wild fluctuations that are impossible to control. Not only will this gentle warming increase and quicken germination rates, it will also increase the soil biodiversity which aids in nutrient cycling. As a result you will have stronger roots, thicker leaves and much better growth. To suggest warmth will cause ‘leggy’ growth is incorrect, this is more likely insufficient and incorrect lighting requirements. Growing seedlings under normal household lights will cause thinner cell walls and overall poor plant health. Thermostat regulated warming will also increase drying of the soil and greatly reduce the likelihood of disease. If you’re heating your soil, room humidity levels don’t become such a problem. But if you’re suffering from dry skin, eyes and throat, then your plants are probably also suffering, so yes you will need to increase the humidity. Hydrometers are very cheap and show constant real time levels, and if you need to increase the humidity in your home, humidifiers are also cheap. For your health and your plants fifty to sixty percent will be fine.
This may sound weird for some but I play music in my grow room almost 24/7. I’ve done grows with no music and grows with music, I swear there is a difference in plant growth and health when playing music, not a huge difference but noticeable. There are actual tracks designed with certain frequencies that plants are known to respond to. I just tell my Alexa to play music for plants and it curates those specific songs. I know it sounds weird but there have been studies done that have proven that plants can respond to certain frequencies and music. Plus, at the end of the day, whether it works or not it can’t hurt any.
For over watering What I’ve found that helped me growing inside under LED in fabric pots was to take them outside put them on a large bath towel folded to the size of the pot then set them on my cement steps without a water basin/flood tray so that the towel and the dry cement will absorb some of the water and just being outside under the sun will evaporate a lot out of the sides of the pot especially if you’re using a high coco coir mix as opposed to a high potting soil mix, coco dries out faster. If its extremely flooded I don’t know, I haven’t really had that situation. For my 5gal fabric pots indoors I normally put 4-5 turkey basters amount of water. At 5 there is just a tiny bit of runoff during mid veg, it should increase the amount during flower or increase the amount of times you water per week because of bigger roots and plants will drink more water so 3-6 Turkey basters 3 during veg 6 during flower is a good amount to start with but adjust it a little to your specific plants uptake needs
…as for the musical influence, I’m a musician and i am fascinated by anything scientific about music and vibrations. PBS has done documentaries on the effects of musical vibrations on water. In part of the tests the research team submerged speakers into containers of distilled water and played several different generes of music each in their own container. After the musical ‘soak’ time they removed the speakers and froze samples of the water. When the team examined the crystalline structures of the ice …the more chaotic the music the more chaotic the ice crystals developed, and the speakers had been removed before going into the freezer. …classical,… jazz,… soft rock, …psych rock, …nordic death metal it was demonstrating the energy that the water held, and if the goal is putting more positive energy INTO the plant for growth, I think it would be more beneficial for the plants if you used music to ‘charge’ the water… not the plant. Same theory as organic living soil ….. you feed the soil not the plant. int this case …you feed the water not the plant. Thats how i understood it to be, check for your self, its a PBS doc. Great website by the way…
In regards to the music question. I was just at SIU talking and touring with one of the grad students and his thesis study is about different hertz/vibrations (a speaker on a metal scrog net) and how it affects the growth. So far he’s had posative results showing that 200 hrtz 15min per hour are good for growth. Something for all of us to pay attention to.
Thanks for repeated information concerning early life stages and helpful products as Rootwise Enzymes and Mycrobe-Complete. Using regular beans and BAS organic methods, high quality flavorful medicine is produced, but quantity not so good. At transplant, small root systems. Mycrobe-Complete used, but maybe not enough. Next Spring will use 20/4 schedule, up from 16/8. Will use enzymes. Does it sound like I’m on the correct path? Should the Rootwise Elixir be given daily? Also how important is watering temperature? If there are live microbes in spring or tap water, then microwaving should not be done. Thanks, Ronnie.
Thanks for the information, these style articles are great, just started perusal your website. I seen u on Mr grow it, 2 excellent shows by u both. I have experience growing mushrooms so I have a decent understanding of temps, humidity, soils etc I’m just about to start cannabis grow so this is all welcome information, especially about growing organically in soil. ☮️
Thank you for this article, Jeremy! It brings up a question/issue I am having. I cannot get anywhere near 72-80% humidity in veg cycle even with a humidifier in my 2×4 tent. The problem is, if I seal up the tent, the temperature rises above 85 and it kicks on my AC Infinity exhaust fan. Consequently, taking out my humidity. Is there a way to maintain the humidity while keeping my temps in check? P.S. if I crack the tent door, I will hit 85 once in a while but with lights on, it hang around 81-83 degrees, which I am happy with. My rH is never higher than 52% with lights on. With lights off, temps go down and humidity goes up to 60% or higher. Thank you for your reply!!
High first off sorry to bother nu on thanksgiving.but happy thanksgiving.i watch u ALOT I have a pb2000 maxisun pro series made my own soil I used one bag peat and 1 bag black cow and half Pearl light I am doing three autos in a 55 gal.barrel cut in half long ways but week 3 the leaves started curling down and in.i keep my temps in 70 to 75 lights on and 65 to 70 when their off…..
What is the pH of the water you use in your soil? I know you said the pH of the water doesn’t really matter too much and that the biology would sort of correct it in a soil grow, but that will only go so far, right? I ask because I’ve noticed that although my water comes out of the tap at 7 pH, after I off gas the chlorine the pH goes up to 8-8.5. Will the biology correct it THAT much, or should I still pH to 6.3-6.8?
80% indoors will definitely cause mold i promise you. Even in veg, thats extreame even for 90%. I understand a vpd chart but so many vary and are not accurate. Its extremely rare in nature that its 80% humidity. That means its pouring rain, very foggy ect. Just my 2 cents from growning for 5 years and many many pounds. Id recommend high humidity of 63-73 max
was looking an old faq vid about purple stems, and this was recommended on the side. and i was like: sure, i’l take that one too. about purple stems and overwatering: i think that was a prob a friend had during the last weeks. although soil didn’t felt soggy at all, no drops came out when pressing a hdanfull, we think it held too much water. clones didn’t grow roots for weaks, and got stunned, begann to get purple stems and leaf veins, growth became droopy with downwards curled leafs. so we transplanted them, back into smaller cups, and they kind of recovered, and at least begann to grow healthy new roots. during that time, we let the big pots get dryer. but after a few weeks, the soil is still moist. so my question is: when does too much moisture in the soil becomes an issue without being soggy? can it be too moist so new clones dont feel the need to shoot new roots? nevertheless, great vids, love the content, helps alot. thx for that.
Sounds great but does the earth follow VPD? I’ve tried this and followed the VPD chart seen no difference. At 85 degrees following YOUR chart 70% is not ideal in veg stage. 60% is more ideal leaning more to the safe side of things. Safe meaning if people live in dry climates…. introducing high levels of humidity in a region that doesn’t see high humidity is a sure attraction to powder mildew
I like you man. I’ve watched you for a while since the first time you appeared on Mr. Growit and thought u where kinda knowitall, Just being straight up with you. It’s the way you come off. But you’re cool homie. I like the way you think.😊 You could’ve been a little harder on the c play music for folier” cat😅 But positive answer and positive reinforcements. Good on ya lol
so question 83 degrees actually gave my plants heat stress ever since i droped it to 75 degrees with 60 humidity shes done alot better, but the soil isnt really drying at a good pace due to the less warmer climate, is there something im missing? or could it just not like the heat? cause the second she hits 80 she tacos.
Hey Jeremy great stuff as always. Seems as tho you spend much of the FAQ vids countering the MISINFORMATION that so prevalent on YouTube n society in general. When we started, there was the pressure to use bottled nutes, bagged “soil” RO water etc. But in doing some research I found Dr Bruce, Elaine Livingston…and you. Understanding the biology that the plants are designed with…how the soil food web works changed EVERYTHING for me. Now I mix my own soil using the Buildasoil way n our runs just get better each time. The nugs get frostier, yields are awesome (2 pounds a run in a 4×4) n the flavors are incredible. I really feel like we get as much outta the genetics as possible this way. Isn’t that the whole point?
Mother nature will torture and destroy everything. Why does a plant outside survive but if my humidity dips indoors I will destroy my crop ?? If I go above 78 I will ruin my harvest. How does outdoor even work if all these swings in nature should kill everything. The stress outside cause dank bud… but indoor is to comfy and will not have same effect or stress induced tarps or flavors just wondering what people think is indoor climate control a scam to cost you cash