The ideal greenhouse temperature for most plants and vegetables is 80 degrees Fahrenheit or 27 Celsius. This temperature allows plants to grow healthily and can be maintained in a buttoned-up greenhouse. Most frost-resistant vegetables can tolerate temperatures at or slightly below freezing, such as broccoli. To make a greenhouse usable in winter, it is essential to keep the interior temperature above freezing with specific adjustments.
The optimal temperature for a greenhouse can vary depending on the types of plants being grown. Most plants thrive in temperatures between 65°F and 75°F during the day and no higher than 90°F (32°C). Monitoring greenhouse temperatures with a good thermometer is recommended, but if you don’t have one, walk inside your greenhouse to see how it feels. If too hot for you, it’s likely too hot for your plants as well.
The minimum greenhouse temperature range for optimal plant growth is around 60-75°F. Maintaining germination temperatures should be in the 15-18ºC range. On sunny days, the greenhouse will warm up nicely during the day, often around 20-30 degrees. For cold-season crops like lettuce or greens, 50 degrees is sufficient, while tomatoes or cucumbers should be 65 to 70 degrees. Citrus trees can also thrive in cooler temperatures.
As a rule of thumb, the difference between the minimum outdoor temperature and that within an average cold greenhouse is approximately 2ºC. Nearly all crops can tolerate an average temperature of 50°F, and cold-tolerant crops can handle temperatures of 35 to 40°F. If temperatures are allowed to build up (typically more than 27°C/81°F), plant damage can occur. For most plants, if night-time temperatures in the greenhouse stay above freezing, but 45-50 F is a better place to shoot for.
📹 Vegetables that Grow in 100 Degree Summer Heat
Wondering what, if anything, will grow in your vegetable garden when summer temperatures soar above 100 degrees?
Should you open your greenhouse every day?
Greenhouses are designed to absorb heat, which is beneficial for plants. However, too much of this heat can be harmful. To maximize ventilation, it is recommended to leave the door wide open or ensure multiple vents are unblocked. A simple rule of thumb for greenhouse ventilation is to ensure at least 20 of the total floor area can be opened. This means that one-fifth of the floor size should be “openable”, and smaller greenhouses may need a higher percentage. This ensures that the greenhouse is well-ventilated and provides adequate warmth for plants.
When can I start using an unheated greenhouse?
It is recommended that the growing season commence in an unheated greenhouse during the late winter to early spring period, typically 4-6 weeks prior to the average date of the last spring frost. For example, if the last frost date is estimated to occur around May 1st, it would be advisable to commence utilisation of the greenhouse in mid to late March. During this period, the greenhouse provides an environment conducive to optimal growth.
How do I keep my plastic greenhouse warm at night?
Greenhouses are designed to retain heat by minimizing heat loss through insulation, such as double-glazed windows or multiple layers of plastic film. Heating systems, such as electric or gas heaters, wood-burning stoves, or hot water pipes, are used in regions with severe winters to provide additional heat. Ventilation systems regulate temperature and humidity, allowing excess heat to escape during the day and preventing condensation, which can lead to mold and fungal issues.
Automated systems open and close vents or fans based on temperature and humidity settings. Row covers and thermal blankets can be used to trap heat closer to the ground, protecting delicate crops from frost damage.
Can you keep plants in a greenhouse all summer?
In late spring, many gardeners plant seedlings in open ground, but it’s essential to use a greenhouse year-round to create an optimal microclimate for plants. The key is to use the summer greenhouse correctly to control the climate conditions, such as darkening with shade cloth, ventilating during the hottest days, protecting plants from high winds and rain, and maintaining humidity levels.
During summer, plants may experience significant stress due to weather changes such as storms, unexpected temperature drops, drought, or prolonged rains. To control these conditions, use shade cloth, ventilate continuously, protect plants from high winds and rain, and maintain humidity levels. Additionally, weeds will be less of a problem as they grow more reluctant and pests will be less likely to invade.
In summary, using a greenhouse in the summer is beneficial for maintaining an optimal microclimate for plants, avoiding significant stress from weather changes, and ensuring the health and growth of your plants.
Can plants get too much sun in a greenhouse?
Sunlight is crucial for plant growth, providing nutrients to shrubbery and flowering plants. However, too much sunlight can be harmful to plants. Greenhouses regulate the amount of sunlight and interior temperature to create an ideal environment for plants. One danger is harmful ultraviolet light, which plants use as a catalyst for photosynthesis. This process converts water, minerals, and carbon dioxide into oxygen using ultraviolet rays. However, an overabundance of ultraviolet light can damage plants, as it overwhelms the internal system responsible for photosynthesis.
Constant and overwhelming amounts of ultraviolet energy run down plant systems, preventing them from efficiently processing elements involved in photosynthesis. This can have adverse effects on the long-term health of plants, as they cannot nourish themselves properly. To protect plants from harmful ultraviolet light, greenhouses should use window shades to regulate the amount of sunlight and interior temperature.
What is the best temperature for plants in a greenhouse?
Most common greenhouse crops require a temperature range of 18-24°C (64°F – 75°F) for optimal growth and quality. Temperatures outside this range can lead to slower growth and suboptimal crop quality. Controlling humidity is essential in greenhouses and indoor growing facilities to prevent problems and inefficiencies. Untreated humidity can cause crops to grow slower, smaller, and reduce their quality. Therefore, growers rarely stray from optimal greenhouse temperatures.
How warm should a greenhouse be at night?
A greenhouse’s ideal temperature at night varies depending on the plants being grown. For most plants, it should be between 60°F to 76°F, never dropping below 45°F. However, it’s crucial to consider the specific needs of your plants, such as cold-season crops like lettuce or greens, tomatoes or cucumbers, and citrus trees. To maintain the right temperature at night, understand your greenhouse’s microclimate, which is influenced by factors like nearby trees, houses, and fences. Remember to never drop below 45°F.
Will a mini plastic greenhouse protect from frost?
Mini-greenhouses represent an effective means of providing winter protection for plants, offering temperatures that are approximately five degrees higher than those typically found in traditional greenhouses. Such structures prevent plants from freezing and can be heated artificially, particularly during periods of extreme winter weather or for plants that originate from warmer climates. It may be advantageous for growers to utilize these greenhouses for their plants.
How much warmer is a plastic greenhouse than outside?
A greenhouse can be up to 30˚F warmer than the outside environment, depending on the type and insulation of the greenhouse. A single-layer greenhouse may show a temperature difference of 5-10˚F, while a double-layer greenhouse can be 9-14˚F warmer. The warmth of a greenhouse comes from a balance of science and design. Sunlight enters the greenhouse through transparent materials like glass or polycarbonate, which absorbs and converts it into heat. Even a slight temperature boost can make a significant difference, especially during chilly days.
Can a greenhouse get too hot for plants?
The sun’s powerful rays can penetrate glass and other manmade materials, damaging plants in greenhouses. Without proper ventilation, shade, or other cooling methods, plants will overheat, damaging their leaves and fruits while drying out the soil. To keep your greenhouse cool in summer, use ventilation as one of the best and most natural ways to keep it cool. It is also important during spring and autumn months when the sun is still powerful. The right type of ventilation will allow you to control the temperature in your greenhouse and provide the necessary warmth for your plants.
What temperature is too cold for a greenhouse?
To maintain optimal plant growth, keep your greenhouse temperature below 3C (37F). Tender plants like pelargoniums, half-hardy fuchsias, and citrus trees prefer a minimum of 7C (45F), and safest at 10C (50F). This temperature is ideal for young plants and plug plants. If you have a conservatory, use it to overwinter delicate plants. Position heaters carefully, placing them in an open, central spot away from water and angling the heater to prevent foliage desiccation by direct airflow above nearby plants.
📹 7 Perfect Vegetables to Grow in Hot Climates
IN THIS VIDEO → Clemson Spineless 80 Okra Seeds: https://growepic.co/3Nf9NzM → Butternut Squash Seeds: …
We put in a greenhouse. In the summer We put shade cloth across some of the greenhouse. We grow our vegetables in tanks that are based on regenerative farming style. The night time temperature is around 70 to 80 degrees. Our daytime temperature is around 100 to 105 degrees with the radiation levels that are amongst the highest in the United States. I have grown celery, parsley, tomatoes, potatoes, blueberries, chard, and carrots with only watering once a week. If you set up your soil with water retaining debris, you can cut way down on your watering plus you won’t wash away all of your nutrients.
Here in Dallas/Fort Worth Texas most of the summer is 100F or above with nights in the high 80s-90sF. Yet, I can grow sweet potatoes with ease if you just water them with high yields. tomatoes are also good if watered. All peppers are good. Summer squash is also good. I am trying black-eyed peas this year to see what they yield. Just try sweet potatoes and you will be happy at the end of the season.
I was hoping to do a tropical garden on my balcony. What was i thinking! Its extemely hot full sun and humidity around 80% in summer. And around 60% in winter. So im growing the vegies. ftom seeds They booting along. Sadly cant have my tropical garden but can have vegies herbs all year round. Happy planting people
I’m growing Virginia Peanuts in 2 gallon containers inside my 120 degree greenhouses and they are blooming and making peanuts like crazy. And my sweet pepper varieties are doing better than my Hot pepper types. Tomatoes need water every other day watering as long as air is moving constantly over the plants.
A couple of other vegetables that like hot weather are eggplant and New Zealand spinach (which is not a true spinach, but can be used like spinach). Tomatillos also do well. Something I learned a long time ago is that large-fruited tomatoes stop setting fruit when the temperature gets high. This is also true of many bell peppers. The smaller-fruited varieties will keep bearing fruit through the heat.
Man I miss gardening. Live in an area without a backyard, just an unfenced lot that the management is super strict on what they allow. Which is nothing, to be exact. Thinking of just doing what i want with a few raised beds, see what they do. I’m in San Antonio, hoping I can get something to actually grow this time around that the heat doesnt destroy!
Good article! I like fried okra but couldn’t find it in any Cajun fast food restaurants. So I planted some in my garden. I got carried away and had 47 plants make it to production. Needless to say I had okra coming out of my ying-yang! Ha! I had and ate so much I got sick of it. I haven’t eaten okra in about 7 years now! Maybe someday I’ll get a taste for it again!
I found out with cantaloupes giving them a moss mulch layer it thrives with the extra moisture but i only got small melons due to growing late and a squirrel 😅 im already starting on my spicy pepper seedlings since my mother plant unfortunately didn’t survive it’s 2nd year and I’ve found out peppers love bottom water tray if grown in pots and afternoon shade
Hi, just saw your article. Trying to get some fall stuff growing in mid-August in the Florida Panhandle. Right now, temps are near 100. What are some seeds that will germinate in raised beds in this heat? I have okra. It popped right up in a few days. I have “pink-eye, purple hull” peas, but I can’t seem to get radishes or other greens like Chard to germinate or they germinate very spotty.
Cucurbits (cucumbers, melons, squashes) are generally pretty heat-tolerant. Winter squashes are not called that because they grow in winter. Their growing season is the same as summer squash’s. But winter squashes can be stored (at a cool room temperature) until winter, and possibly even through the winter. This is mainly because they have thick, waxy skins. By the way, a pumpkin is a winter squash. Particular varieties will be called “squash” or “pumpkin,” but that’s a distinction without a difference.
I love purslane. It’s growing all over my property. I love to make pesto with it and it’s the only thing that’s growing right now. I am so pissed off, nothing is growing. This is horrible and my house was flooded last winter and I swear it left a 3-in layer of concrete dirt crap that ruined my soil that I had already amended and turned over. I can’t seem to get anything to grow everything stunted and it’s freaking pissing me off. Tomatoes are growing. I got lots of tomatoes but nothing else. Oh and pumpkins pumpkins neverending supply of pumpkins. I didn’t want pumpkins this year but they won’t stop growing because they were in my compost and last year. Anywho? I’m the angry gardener
We are in vegas 117 F has become our all time normal temp😢 all my rose plants are dried and about to die. Toamtoes hardly flower and got just 10 tomatoes overall whu h I couldn’t even harvest because of hot temps.We have shade cloths but the problem is one wind can pull them off from ties… I don’t know how to manage my yard. I love gardening but nothing seems to work..pls help.
In the South, where heat and humidity are the problem and nighttime temps don’t drop below 80 until at least September, in my experience, the things that really thrive are peppers, eggplants, certain squashes (spaghetti squash grow like weeds), mouse melons, sweet potatoes, okra, pole beans, red noodle beans, and cowpeas. If you live in a particularly hot and humid place, I especially recommend noodle beans. I put mine on an 8 foot tall bamboo tipi trellis and they swallowed it. We had more beans than we knew what to do with! They produced 18 inch long pencil thin purple pods for three solid months! We even ended up freezing a couple gallon bags full of cut beans for later.
I’m in Sweden. I tend to grow Chilli’s in pots, stick them out on the balcony in the summer for them to get the all day and most of the night sun.. Then when it gets cooler, bring the pots in. To save them from the dark and frozen conditions. Trim them if they’ve got a bit dangley, and when it starts to warm up again straight back out on the balcony, and cut them into a better shape. As they’re a few years old they recover really fast from being cut back and bush out really well. Have Habanero’s, some finger chilli’s and currently growing some Bhut Jolokia. Love growing all Chilli’s for making hot sauce.
Topping peppers makes the plant bush out more, but also increases the time to harvest. In my opinion, don’t top at all if you’re in zone 8 or colder. It only makes sense for really warm zones. If you’re going to top, only do it to plants that typically grow tall and lanky. Typically capsicum annuum. Don’t do it to varieties that are already bushy, like Chinense and Baccatum. Especially don’t do it to super hots, because your fruit won’t ripen because your plant’s growth will be delayed.
Louisiana grower here – amaranth and Egyptian spinach is a good spinach substitute for greens in the summer, Everglades tomato does well in the heat, and tromboncino squash and cucuzzi squash are more vine borer resistant. I grow pumpkins almost all year because we can, and eat those like young squash. Zinnias won’t quit if you deadhead. Okra is ok, sweet potatoes you can do any variety but I love the white- and then for fall crops for us it’s almost time to plant seeds (in July) for brassicas since our cold window and frost are so close together and weird 😅
For some time I had been dreaming of growing eggplants but I thought I would need to be living somewhere more southern location than Finland to be able to do it. This spring I realized that what the heck, I have a glassed southern facing balcony that heats up during the summer for temperatures that aren’t comfortable for humans so it must be adequate for eggplants… And it was! I have already harvested two sizable fruits and more is coming. They aren’t patio varieties but just normal ones. One hybrid is a long narrow style and one is the black beauty. I am a pretty proud eggplant mama now🍆☺️
I’m in the Long Beach area and just started turning my apartment balcony into a vegetable and herb garden. It’s been a couple weeks since starting and your website has be a great source of guidance. It’s my first endeavor into gardening and I’m already learning some of the mistakes I’ve made. It’s so much fun though and I’m excited to see how things turn out. 🍻😁
Due to family needs I had to leave my garden for a month. The tomatoes had been given a string attachment to conduit 6 ft above. When I came back the raised bed was out of control. 2 weeks later the trellis went partially down in a windstorm. It took my full hanging weight to pull it upright again. There are probably a 1000 cherry tomatoes set on plants that are 11 or 12 ft in length. It is a jungle but no disease I attribute to starting in 32 inch tall raised beds and some early low area trimming.
Learn something new every day! I did not know you could eat the whole sunflower plants 🌻 😮. I planted one of the max sunflowers a few years ago & the birds have scattered them & I have an entire bed of them 😂. I’m going to try to transplant clumps of them & see how it goes. The roasted head 👀 delicious 👵🏻👩🌾❣️
I live in a sub-tropical zone. My “go-to” bean is the preninal (7 years) “Madagascar Bean”, drought and neglect tolerant, and in my climate zone crops twice a year. The young pods can be used like string beans, and the dried (on the vine) beans (bigger than broad beans) can be soaked and used as a base for a multitude of dishes. I liked using them as a basis for soups (esp. pumpkin) and in sauces (pasta)
Another plant that I know that loves the heat and hot climates would be Strawberries. For all of the fall and winter they are dormant and in spring they grow leafs but nothing really else. But when it hits summer it gets very hot and they start growing multiple flowers and also branch out and make new Strawberry Plants.
I live in an area where it’s extremely hot and humid in the summer. For example, it rained last week, and the temperature the next day was 89° with a real feel of 114°. I grew some Candyland tomatoes for the first time, and holy crap they are still THRIVING in full sun even on the hot days. I have one that has been in the raised beds since April, and it’s absolutely massive and still producing an insane amount of tiny, super sweet tomats.
This is perfectly timed for us. Just hours ago my return to gardening got absolutely destroyed by 100 mph surface level winds. I can’t sleep so I figured I’d at least find some suggestions that could handle our hot southern Midwest heat. Your suggestions are just what I needed to feel better about salvaging some grow time this year. THANK YOU!
Love this list! Growing Malabar spinach for the first time this year. I’d add the loofah too, can’t remember the true name. Young fruits are eaten like zucchini in Indian cooking and if u miss it becomes the sponge. A few years ago when we had 6 weeks of 100 degrees in southern cal, it was my only veggie garden plant that was not just happy, but grew like crazy!!
I STAND BY MY OKRA WHOOPING!! i’ve been doing it for multiple seasons ever since i experimented with and without. noticed at least a 30% increase of yield (by number of fruits) but typically more in the 60-80% increase range with whooping! i whoop each plant for about one minute each in the morning and at night right before the light goes out. additionally make sure all the soil is turnt over each time.
If you live in a really hot area without much rain fall, peppers actually do surprisingly well in the shade. Some birds ate some of my hot peppers and dispersed the seed under some orange trees of mine and they did great without any extra care from me. The harvest/growth is a little slower, but the plants did way better through a dry spell than plants that I had in the full sun that I watered. I tried malabar spinach and I found it nearly flavorless. It’s only similar to real spinach in that it’s a leafy green. I wouldn’t plant it again.
Can’t say enough good things about the Kentucky Wonder Bean, in a hot climate. Just tried it by chance, and it just thrived, and has been spitting out beans for almost 2 months now and still going strong…just from a couple plants. Wonderful for those with smaller garden spaces, as just a few plants will make at least one “side dish” portion every few days.
Been getting into local sustainable crops. Trying amaranth (red) this year instead of sunflowers. ended up with a mix of both, its looking and tasting good :). got the seeds thru your store. Very interested in the seed harvest this year for my already established staples. My Radish’s have already bolted, some before bulbing out (first year in a raised bed, may have slightly over sowed). I also planted to many varieties of corn too close. My popcorn-Aztec colored hard-yellow sweet – Painted hill Sweet rowing is going to mix up pollen wise. Luckily i didn’t use all my hard seed. I will quarter out my garden next year and spread them out as to not x-pollinate. Live an learn lol. tho i am kinda curious what my sweets are going to taste like with a touch of hard/popcorn mixed in. prob horrible but… shrug maybe get a few good ears still. No matter what the chickens will love em.
I am gardening in Central Virginia – 3 to 4 months of hot humid tropical weather, and I am always looking for plants that enjoy that kind of weather, from other regions and cultures Here are some further suggestions. Y’all had mentioned eggplant – I would like to emphasize that. There are a great many cultivars in an amazing variety of shapes, sizes, and colors. Many, if not most of them are, in my experience, more productive and flavorful than the standard Black Beauty. When night temperatures do not go below 75º F beans in the Phaseolus genus, such as the Kentucky Wonder type, tend not to set beans. Bloom like mad, but no beans. Chinese Long Bean adores heat and high humidity, and I suspect it would be fine with low humidity given adequate irrigation. The cultivars I find to be the best eating quality are Liana, Gita, and Orient Wonder. In that same category are the many varieties of that same genus (Vigna) known in the U.S. South as field peas, cow peas, southern peas &c. The famous black-eyed pea is one of those, but there are many others. They can be eaten as snap beans (when VERY young) shell beans, or dry beans. One of my favorites is the cultivar Zipper Cream Pea eaten as a shell bean rather like one would eat English Peas. In fact, the flavor is somewhat reminiscent of English Peas. They make very good soup beans. Amaranth, known, in some parts of the Caribbean, according to my understanding, as callaloo. (In other parts of The Islands, callaloo refers to the leaves of taro/dasheen/elephant ear, a very different plant.
I live in zone 9a in central Texas. We get temperatures up to 110° for months at a time during the summer. Peppers don’t fare as well in that kind of heat, but I’ve planted them in an area this year that gets the first shade in the afternoon and it seems to help them from wilting too much, but since temps don’t drop under 80° at night, we still get a lot of flower drop. Peppers and tomatoes need temperatures to drop significantly at night in order to have fruit set. My butternut squash also can’t handle the heat 😂 Here at least, beans, blackberries and tomatillos have done really well. They don’t seem to mind the triple digit temperatures at all and keep up production!
Love your articles! I need some pruning advice for a Black Diamond Thornless BlackBerry. There is little information on this bush in regards to pruning. I pruned last year according to the general rule of thumb for pruning blackberries but if I prune this next year there will be no prima canes. So yes, any advice would be appreciated. Currently the plant is thriving and is beautiful.
The term ‘okra whooping’ is not one I’m familiar with but I have heard ‘spanking’. Not just for okra but for all plant starts such as tomatoes, okra, peppers and any other garden plant with a stalk. The purpose is to make the stalk stronger and more resistant to breakage due to high winds as well as making it healthier and resistant to disease. When flowering, this method also helps the blooms pollinate since most peppers and tomatoes are self pollinated. The method just helps the pollen transfer from the male part of the bloom to the female part. It does work. What I do is the moment the seeds germinate, I set a fan on low and a few feet away and if you have a model that oscillates, even better. I notice the stalks develop thicker stalks when this is done.
Do you have any more collabs planned with the woman from Vancouver, for us colder/shorter growing season folks? Also, can you do some articles on automated irrigation for beds? I have set up a system, but it’s really hard to balance the water output from all the different heads, or get the heads to disperse water far enough to cover more than 1 plant per irrigation tip. Do I really need one for every single plant? (Sorry if you already have vids on the topic, didn’t find one at first glance)
Growling up in South Carolina, I love that you included Okra. It is probably a little bit of an acquired taste though, and so many people I know complain about texture and it being “slimy”. Of course, that is more of how to prepare it. I did cringe a little at how Jacues pronounced Clemson. As a native Carolinian, we all know that there is an invisible “P” in Clemson. So it is pronounced Clempson!