Heat tolerant vegetables

Some of us are getting blasted by Summer heat these days. Upper 90s - 100+ during the heat of the day. What vegetables are you growing that seem to like the heat?

Right now for me, Malabar Spinach and Armenian Cucumbers are doing the best.  Eggplant are growing lots of leaves but not setting fruit - this may be due to too much nitrogen.  I hope eventually they'll decide to set.  Peppers are also doing well.  Everything seems to prefer plenty of irrigation. My main fault as a gardener is probably  not watering enough - my husband says "The green thumb is the one that turns the spigot."  

I have a patch of Sunroots that seem to be doing quite well, I hope they're making tubers down there.  Sweet Potatoes are growing but not fabulously.  Melons are growing but not yet setting fruit. Luffa is growing like crazy but not setting fruit yet.  Tomatoes are really limping this year, but I understand most varieties don't especially like the heat.

Garlic Chives and Walking Onions seem unfazed by the heat - the Garlic Chives are doing especially well and I'm definitely going to work harder to incorporate them into the menu.  I have a weird habit of not picking vegetables that are doing well - like I feel guilty killing them - but in the case of Garlic Chives they can be cut at the base and grow back.  Same with Walking Onions.  

What are you growing in these high temperatures and what is being productive?  How are you keeping the garden from just keeling over in the heat?

My Okra are doing quite well in the heat. They seem to make giant fruit overnight (although it's probably just because I'm not diligent in checking them everyday).  I just pulled a couple okra yesterday that were 7-8 inches.  Of course this is the one thing I planted that I don't really care for...

My pumpkin plants are growing like crazy although they have not started to fruit yet. And I just put out some sweet potato slips that haven't keeled over from the heat so that's good.  I had some pea/bean plants (15 bean soup) that were doing really well until my goats found them. Not vegetables but I have catmint and lemon balm that are doing pretty well. The herbs seem pretty unaffected by the heat.

I have been watering quite a bit this year so I think that is the only thing keeping the stuff in my garden alive. Last year I watered very sparingly and everything basically died.  

Nothing seems stressed by the heat so far but I don't have a lot planted. Blackberries,  asparagus, tomatos, Luffa all doing good.

We've pulled 11 ripe cantaloupe from the garden this week. I think that we have one left out there.

Outside of that everything seems to be limping along. I fertilized the tatume and now have several female flowers developing.  Last year I planted my first tatume in August, hardly watered them at all. They survived at a tiny but healthy size and then took off as soon as the fall rains arrived. There was a very short window between the first rains, and the first frost but I still had a harvest from them. With that in mind I've planted a few more seeds this week.

Squash vine borers have found the Seminole pumpkin, but it seems to be pulling through and maturing the four pumpkins formed this spring. I haven't decided if I'm going to do a second planting of these this year. I definitely plant to grow them again in the future.

Kentucky wonder beans and Scarlett Runner beans are both healthy but not forming beans until the weather cools off again. That's to be expected of both of these. They gave good spring crops and I expect even better fall crops.

Our long beans are producing a little bit, but as they are covered in flowers right now, I'm hoping they're about to increase their productivity.

Neither eggplants or peppers are producing, but both look healthy.

I have volunteer sweet potatoes that I'm going to start harvesting greens from, just to keep them from overwhelming the snake melons and tatume.

I've actually been disappointed with the snake melons this year. Both vines are healthy and covered with flowers, but I've only picked a couple of fruit. They're another plant that I just have to hope is waiting for fall.

None of my onions bulbed up this year, but they're not dead yet, so we're taking a wait and see approach.

One of my new amaranth varieties has a few lovely large plants that we've started to harvest from. They're a nearly iridescent dark green on top of the leaves and a nearly iridescent dark purple on the bottom of the leaves. Combine those with the malabar spinach, and sweet potatoes and I think we're finally into the summer greens season.

I've been trying to over summer (like overwintering for you northerners) kale, swiss chard, and collards. Both the kale and the collards are surprising me with fresh flushes of growth. Maybe the heat is finally too much for the cabbage moth.

So all told, I'm mostly waiting on fall. My garden isn't dead but the majority of plants do seem to be napping.

I'm finding over time that it just helps to be satisfied and document what crops are robust during variable seasons and which ones are highly influenced by the swings of the seasons.  The potatoes that we've kept using for seed year after year are still performing good in this current dry year, even though they've survived wetter years (photo). So they've become pretty well adapted, along with the paste tomatoes, to the vagaries of the local climate.

Okra, sweet potato, water chestnut, Seminole squash, cowpeas, yard long beans all thrive in heat.  Bell peppers grow well, but won't set fruit when temps are in the upper 90's.  Summer squash grows fine until the borers get them.  Tomato plants suffer and don't set fruit, current tomatoes have no problem and continue setting fruit all summer.

My Red Noodle Beans, which are supposed to be so heat-tolerant and productive, suddenly stopped producing and have mostly died.  Not sure what's up with that.

On a happier note - my Eggplants are setting fruit!  Some people think Eggplant is gross but I love it.

this has bean a green bean year for us. The beans cukes,maters are finally coming. last of the cabbage was harvested today. squash corn amaranth all finally gowing good. Last week was the first time we watered and it rained an inch yesterday.lol

Hello Tyler,

We're in the same geographic location (our ranch is outside Fredericksburg TX). We get pretty much the same weather as you apart from getting less rain since we're farther from the gulf of Mexico. At the moment, we have tomatoes to harvest, ground cherries (not very hardy), okras, jute (aka Egyptian spinach, leaves are delicious and is extremely hardy), sunchokes (aka jerusalem artichoke), malibar spinach, melons, sweet potatoes, corn, cucumbers, Chinese noodle beans, melons to be harvested in a month or two and so much more.

We've been harvesting tomatoes every year during this time of the year without much problem. If I may suggest looking into heavily mulching your ground with wood mulch (straw will help to feed the soil, but may be more limited in avoiding evaporation in this crazy heat). I have about 4" of mulch everywhere something is grown. This allows us to water much less frequently than everyone around here. We water our fruit trees around once a week from June to August and some were just planted from a container a few months ago (6ft tall trees in average, that haven't rooted extensively yet). That's very little watering for these months here in Texas. What we also did is created as much natural shade using bushes and trees, so we don't do much row gardening and we intermix our trees (native trees, fruit trees and nut trees) in between all the other plants. The extra shade will give you a very good buffer for water. Shade provides more benefit than mulch to limit evaporation, but until you have a good shade umbrella, I would definitely think of watering more in the meantime. Even though shade is more efficient than mulch in the end, I wouldn't go without mulch ever, even after all places are partially shaded. The summer heat is just too hot to go without it and we don't have much rain for many months, which really doesn't help the situation.

Hope this helps.

Jan

Jan Corriveau wrote:We water our fruit trees around once a week from June to August and some were just planted from a container a few months ago (6ft tall trees in average, that haven't rooted extensively yet). That's very little watering for these months here in Texas.

To me that looks like a lot of watering!  Clearly I need to change my standards of what counts as "a lot of watering."  I don't think I've ever gotten over the $400 water bill we got one month back when we lived in California.  We've been in Texas for years now, water is cheap, and it's still hard for me to allow myself to water enough!

Hello Tyler,

I see your point about a heavy water bill. That must be really unpleasant. Our long term objective is to never have to water at all and only rely on rainfall, similar to the concept in the movie "Garden of Eden" where even though the guy gets something like 15-20" of rain a year, he doesn't ever water and he's growing a quite large garden. He lives much more north from us, so we have a bit of a harsher summer climate down here. My biggest challenge is that my land has a maximum of about 1ft of clay soil and only limestone right under. So very little thickness to retain water, hence us having to water once a week in the middle of summer, until the new trees have a bit more established roots. The trees I planted last spring can go quite a bit longer than that though and could pretty much get away with no water outside the summer zone.

I believe you live around Bastrop? If that's the case, I have a good friend that lives there and his soil is very different from ours, clay down as long as you dig and should allow much more water retention in your case if well mulched and shaded. That's what I was trying to get across. You should be able to get away with much less than what we have to do if your soil is like my friends place.  You may already do all those things and I also went a bit away from the original subject ).

Back to the original subject. As far as really hardy and easy to grow in summer crops, I'd add Jute to your list for sure. I can even send you some seeds if you give me your address as I have a ton of them. It's hardy like heck and no sun is too much. It's also a very fast grower and you can start harvesting very early. There's so much Malabar spinach I can eat, so I have tons growing, but much prefer Jute for the taste.

Cheers

Jan

We're pretty much due south of you in Kendall County, with shallow soil over limestone. Our soil is clay, good soil but lacking in organic material, which I'm improving. Thanks for the suggestion of jute/Egyptian spinach.  I grew it a few years ago and plan to try it again next year.  I have a really black thumb, so it sort of doesn't matter what I try to grow, I'm more or less bound to kill most of it, apparently.  Maybe it is from just not watering enough!  My garden is doing much better since I moved it from an exposed position to a place among trees, and put in buried wood beds.  But still it needs watering under these hot dry conditions.

My ideal is also a non-irrigated garden but I don't know if that is plausible growing standard vegetables here.  There's no comparison with Paul Gautchi's Back to Eden garden - his 15 inches is like 30 inches here, because of the low evaporation he has there in Washington.

We moved 17 months ago and this is my second year garden. Last year I got nothing. Zip. Zero. This year, about half of what I planted failed, so that means half is producing. I planted a whole packet of yellow squash seed and harvested over 220 yellow squash! It is about done. The long beans are just starting to produce and will pound us with green beans until a hard killing frost. Violet's Multicolored Butterbeans are just starting to produce also and will make until a killing frost. Purple Cherokee tomatoes are the hero this year, have 36 plants and they are making like mad. I dehydrated 25 tomatoes today and will dehydrate another 25 tomorrow. I oven can them at 300 degrees F for 15 minutes in half pint jars. I have some calico peas that are vining all over the place and they are starting to make. I think I'll have enough to put some in the freezer. The heat is horrible right now, but this is what is producing for me right now. Forgot to add-I am north of Tyler, Tx.

Dana Jones:  "I oven can them at 300 degrees F for 15 minutes in half pint jars."

Dana, I don't have a pressure canner and have been looking for ways to preserve tomatoes, so will try the dehydrating technique. Thanks!
Was interested in your oven canning suggestion as well, but found this at the Penn State county extension website and thought you'd want to know:

Oven Canning
First of all, placing jars in the dry heat of the oven may cause the glass to crack and shatter causing injury to you. The Jarden Company that manufacturers most  canning jars in this country states emphatically that it is not safe to heat glass jars in the dry heat of an oven. Jars are not designed to withstand oven temperatures and can break or even explode causing injury from broken glass.

Secondly, dry heat is not comparable to the moist heat of a boiling water bath. Processing in an oven will not heat the contents in the coldest part of the jar in the same way as boiling water.

Thirdly, oven heat will not increase the temperature inside the jar above boiling to be adequate to destroy botulism spores in low acid foods. Only in the enclosed conditions of a sealed pressure canner will you be able to increase the internal temperature to 240°F. Oven canning is not recommended!

http://extension.psu.edu/food/preservation/news/2014/avoid-open-kettle-canning

Back to the topic of heat-tolerant veggies:
I'm way north of both Tyler & Dana in western Arkansas, so I get much more rain, but with my silt/clay acidic soil (with rocky substrate) drys out in July, August and most of September, I definitely have to water to keep annual vegetables and newly established trees/bushes from dying. What everyone is planting further south of me is of great interest. Thanks, Tyler for starting this thread! Both you & Dana seem to have better luck in the shade. I have gardens in full sunshine and part in the shade a a giant oak. I lived in New Mexico & Texas most of my life and retired to Arkansas fairly recently and thought the tomatores would do better in the shade of the oak (not under the oak). Nope, they seem to need full sunlight in order to get a good start, then they need watering to keep them alive during the hotter months! But the tomatores in the shade of the oak are still behind in plant growth and production. At least they need less watering .  Dana, appreciate your tip of wood mulch versus straw mulch for water retention.  

These are the vegetables that are tolerating the heat here: Lisbon onions (season ending, but still hanging in), Purple Hull beans, Red Chinese Noodle Beans (red yard-long beans) and cherry tomatoes (lots of problems with my slicer & beefsteak tomatoes, from pests that aren't bothering the cherry tomatoes). All lettuce greens have bolted. Thinking that Malabar Spinach and jute sound like good choices for next summer!
 

Merry Bolling wrote:
Dana Jones:  "I oven can them at 300 degrees F for 15 minutes in half pint jars."

Both you & Dana seem to have better luck in the shade. I have gardens in full sunshine and part in the shade a a giant oak. I lived in New Mexico & Texas most of my life and retired to Arkansas fairly recently and thought the tomatores would do better in the shade of the oak (not under the oak). Nope, they seem to need full sunlight in order to get a good start, then they need watering to keep them alive during the hotter months! But the tomatores in the shade of the oak are still behind in plant growth and production. At least they need less watering .  
 

There are a lot of variables that affect how or whether you can succeed by planting full sun plants in the shade. One of them is time of year. There are plants that I can start before our trees leaf out (if I'm prepared to cover from frost) that will do much better in the shade during the hottest time of the year. They must have that initial period of full sun while the days are shorter. For other plants (including tomatoes) the key is to plant them on the edge of the shade where they receive dappled sunlight for nearly a full day. There's also the option of taking advantage of a shady spot to start heat sensitive vegetables before the weather cools and days shorten in fall. Plants like broccoli can start establishing good roots and growing leaves and by the time it's ready to flower, the leaves are falling and the plant is now receiving the full sun of a gentler season.

Eventually I plan to experiment with growing plants under an olive tree which is maintained to keep dappled shade under it's canopy. I've seen this down successfully in another garden in Austin. Other trees that filter the sunlight through it's branches without creating a dense shade include mimosas and mesquite.  Most common shade trees (oaks, maples, ash) are valued in part for how much sunlight they block.  I wouldn't expect many vegetables to do well under those conditions. Even in my own garden I only plant gardens at the edge of my pecan tree's canopy. Much of these are filled with greens that I only harvest in winter, after they pecan tree drops it's leaves these plants are much more vigorous than in the shady conditions of the rest of the year.

. Casie Becker: "For other plants (including tomatoes) the key is to plant them on the edge of the shade where they receive dappled sunlight for nearly a full day."  

Thanks for responding with shade techniques, Casie! Wasn't quite sure where "the edge of shade where they receive dappled sunlight" meant exactly.  Does that mean at the edge of the tree's canopy (tree where canopy is open enough to provide filtered light, sadly not my oak) where the vegetable would get several hours of full morning sun and then dappled shade? Or are you saying to plant the vegetable beyond the canopy edge of the tree, but in its afternoon "shade shadow" at a point where the vegetable would receive dappled shade for most of the day?

Probably depends of the vegetable involved and whether the root systems of the particular tree/vegetable combination might interfere with each other, true? My newly established trees, of course, are much more affected by root competition from other plants than older trees. In any event, your tips reminded me that tomatoes currently not producing as much under the dense shade of the oak, might do better than my full sun tomatoes if I keep experimenting with different trees or densities of shade. Here's to continued trial & error!!  

If you're looking for a starting guide for your own experiments growing in the shade, you might look into what local nurseries do in the summer. Around here, summer shade houses are just as important as winter greenhouses in keeping plants going. The professional operations have already done the trial and error to determine what percentage of available sunlight is actually necessary for different plants in our area, as well as how much light is too much for other plants.  

I think I've wandered away from the topic of heat tolerant vegetables for this. If you want to continue this discussion, I'm posting the rest of what I started to say in this thread https://permies.com/t/8757/organic/growing-shade#488464  which has an older discussion about growing vegetables in the shade.

Merry Bolling, I don't try to can in the oven, I only heat the jars of dehydrated tomatoes long enough to pop a seal on the lids. Any higher temperature and any longer time, and the tomatoes burn. I have canned tomatoes all my life without a pressure canner. There is enough acid in them to keep from spoiling. Hot water bath is generally enough for tomatoes.

We haven't had any rain in a long time and the only thing we have left ares tomatoes & bell peppers.

I don't use my oven in the summer and I am too lazy to pressure can in this heat.  I made squash relish and pepper relish and just let the jars seal from the hot liquid and then put them in the fridge.  They get eaten before they can go bad.