help for gardening in a dry sunny yard in Waco, Texas

I'm looking for advice/encouragement for my sister, a transplant from the Midwest, who is very sad because her garden in Waco keeps dying. I haven't seen her yard, but I understand that it is very sunny and has almost no shade, at least over the areas where she's planting. She's on a suburban lot, so not a ton of space to work with. She follows recommended seeding/transplanting schedules from the local ag extension, but her tomatoes die in the heat instead of producing. Her squash and corn also die in the heat. Apparently she did get green beans to produce before they died. She tried mulching last year but said it didn't seem to make any difference and the plants dried up and died anyway. My guess is she needs to improve her soil and think outside of the traditional temperate climate gardening box. Can you tell me what you do that is successful at growing food in Texas, or point us to books or websites that will give detailed instructions?

We gardened for several years just south of Waco.

My advice would be to watch the plants as they will say when they want to be watered.

If the plants start to look sad, like a little wilted that is when to water though it is usually best to water in the mornings.

I am now over 200 miles from Waco though I would suggest that this is an exceptionally hot summer.  Our temps have been over 110'.

Yes, soil health may have a lot to do with helping the plants survive.

I would say that getting wood chips to use as mulch will really make a difference.

What type of watering system does she use?  How often does she water?

Has she checked her soil PH?  Since the water is filtered through limestone rock it is probably high in calcium.

Shade cloth on the western side of garden beds and deep (~6 inches) of mulch. Our best performing beds are in almost full shade after 2pm.

I like the books Texas Organic Vegetable Gardening and Texas Gardening the Natural Way both by Howard Garrett.

Waco gets two times more rain than my location and also does not experience 5-6 months of not-a-drop-of-water drought. The humidity is also twice as high.
I tried very hard for two years to have any crop. Here are my findings for continetalized Mediterranean climate:

1. Direct seeding. Avoid transplanting from perfect to harsh environment. It also saves a lot of time, energy and equipment. Plant seeds as early as possible.

2. Plant as many cultivars and species as possible to see what grows. Repeat for few years to adjust for weather changes year to year. Do not believe statements on the seed packages that they are drought tolerant. You have to find the seeds that will work for you.

3. Partially forget about vegetables that grew in the Midwest and you loved them. It will not work the same way if at all.
I moved from Midwest myself and now consider its soils and weather to be the paradise of vegetables. There I did almost nothing to produce everything and in large amounts

4. Load the soil with organic matter - rotten woodchips or fresh, composted manure and some fresh, chopped grasses, cardboard - basically anything and as deep as you can.
This spring I had several surprise vegetables growing in various spots from previous year unsuccessful sawing. One Hokkaido pumpkin started growing by a blackberry that I planted in March. I have prepared the fruit bushes bed by digging out the soil to the depth of 20 cm, then mixing with composted manure and wood chips. I mulched 5cm thick around. I irrigate the fruit bushes once per week (now twice, because it's hot). The pumpkin grew into a 4x4 m monster plant with no other help.
This is a living proof of a difference between native soil and an improved one.

5. Plant sunflowers. They grow very fast and will quickly provide shade and some wind break. And later seeds for chickens (I don't eat sunflower).
Cucurbits also grow fast and will also provide a shaded canopy for more sensitive species. Next year I'm planning to plant 100 melons.
I have constant drying winds throughout the day and all tomato flowers dry before being pollinated, so every morning I started shaking them gently and I managed to have 6 fruits started so far (thanks Jen!).

6. Create mini berms around each plant (or row), so the water will stay where it should.

7. Avoid planting in elevated beds - they dry quickly. Try to do the opposite and plant not higher than ground level.

I'm in Portugal, but I too have had to adapt my gardening techniques to a new, hot climate with an unforgiving sun.

This is what I've found:

Avoid raised beds, they just dry out and become concrete. Dirt turns to dust on hugelkulturs and blows away, no matter how many weeds and whatnots you let grow on it to try and retain the soil. Also the environment is not moist enough for the wood to rot down like you want. Avoid.

Waffle gardens - basically the opposite of a raised bed - work much better. Dig square ditches in a grid pattern, using excavated earth to build up little walls around the holes. These retain moisture and shade the roots. Improve the soil within the holes. You can combine this with square foot gardening if you like.

Offer incomplete shade to the primadonna plants that need it (maybe tomatoes in your case). This can be as simple as building a little hut structure and laying a few bushy sticks over the top. You don't want to block the light, just weaken it slightly. You can also be strategic and plant things behind other plants that block the sun. Like someone else here, I am using sunflowers for this. They are incredibly hardcore plants that barely need watering - they will be great for your climate.

I have tried using an Olla - it does not seem to do much at all. Your mileage may vary.

Be careful with mulching as if the soil dries out under the mulch then when you water, the water will run off the mulch and not penetrate very well. It also seems to prevent the soil absorbing dew and such in the mornings, if there is any. Only use mulch in a bed that you're going to commit to keeping moist on the surface of the soil, which is very hard in my climate.

I tend to leave most weeds - especially low growing stuff like chickweed - as it stops the soil turning to dust, shades roots and helps to retain moisture.

Polyculture works quite well. I sow everything fairly randomly - not everything survives but a lot of things find a niche in between a bunch of other plants and do really well. I observe what seems to work. For instance - when I first got here I planted a small area with just beans in chickweed - the beans all dried up and died. Same beans, next bed over, mixed with potatoes and sweet potatoes, cabbages, courgettes and completely untended weeds and grass - everything lived, is still hugely productive and green and does not seem bothered at all by growing amidst 2ft grass and fat hen. My neighbours hate this - whether they believe it is an act of laziness or ignorance - but I get loads of food out of there, it's fertilized only with goat poo, no pesticides, and everything is incredibly healthy - so they can keep their chemicals and say what they like.

Don't bother transplanting - unless you baby everything for a week or more, they all tend to die as they don't generally develop a strong enough root system to cope. Even if they survive, they end up stunted. Direct sowing is the way to go. Trust in nature.

This is a longer term strategy, but you should also look at landrace gardening. I have brought my seeds from the UK, mixed them with seeds bought locally and some bought online from further afield. If anything is doing really well, or if I like the cut of its jib, I tie a piece of wool around it and ensure it is left to set seed, which I will use next year. This is my first year here, but I am hoping that next year's seed will be better adapted to this place and have hybrid vigour.

Hope that helps and hope your sister finds her gardening groove!

Are the plants dieing from:
slugs
voles/moles/rabbits/etc
lack of water
aphids/bugs
sunburn (watering the leaves at 12-noon, then having that water boil the leaves)
alkalinity (There was buried drywal where I was trying to grow and I keep on wondering why the plants died/thrived 6inches away)
too much nitrogen

Do you have a timeline of how long they survive and what variables change (length of day, avg temp, rainfall pattern, powdery mildew season)

My solution would be to compost all of my kitchen scraps (tomato pulp, squash seeds, onion, garlic, celery ends, carrot tops, sweet potatoes, irish potatoes, etc). And see what sprouts and do well that year or the following year. Most of my garden is from wild volunteers.

For the 1st year she can also focus on support species like legumes/beans, daikon radish, herbs (mint, lemon balm, winter savory, thyme, rosemary, oregano, lovage, water celery, celery, cilantro, garlic/onion/chives). Then after those survive move on to heat loving plants from the spinach family, maybe some pepper too.

S Bengi wrote:heat loving plants from the spinach family

What heat-loving spinach relatives do you recommend? I am trying to grow chard, as it's supposedly a little bit drought tolerant, but it doesn't seem to like the heat and is very wilty, even in the shade. I have some amaranth too, which does fairly well, although it needs a lot of watering before it gets going.

The only other truly spinach-y type thing I can grow well at all seems to be New Zealand Spinach, which actually is from an entirely different plant family. Not complaining though because I think I actually like it better!

In parts of the world, raised beds don't work.

For the part of Texas that Waco is in the ground is full of limestone.

That might be Phoebe's sister's problem.

Plants don't grow well in rocks.  Plants can grow in rocks just not very well.

We only grow vegetables in raised beds because the soil is poor.

When we lived south of Waco we had the local dirt company bring in what they called "Garden Mix". That was what filled our raised beds.

Unless all plants are drought resistant, the plants need to be watered.

This guide from Bonnie Plants explains how much water is needed:

watering your plants is an inch of H2O per week, either by rain or watering; in arid climates, it is double that. In hot weather, vegetables need even more water, up to about ½ inch per week extra for every 10 degrees that the average temperature is above 60 degrees.

https://bonnieplants.com/blogs/garden-fundamentals/how-much-water-do-vegetables-need

As S Bengi suggested there are a lot of different factors as to what her problem may be. Especially the alkalinity because the soil is alkaline and the water is alkaline.

A soil test would be advisable and knowing the soil's PH.  I am not sure thought the local ag extension agent might be able to help with those.

A  little vinegar dribble on the soil will bubble showing that the soil is alkaline.

Rudyard Blake wrote:

S Bengi wrote:heat loving plants from the spinach family

What heat-loving spinach relatives do you recommend? I am trying to grow chard, as it's supposedly a little bit drought tolerant, but it doesn't seem to like the heat and is very wilty, even in the shade. I have some amaranth too, which does fairly well, although it needs a lot of watering before it gets going.

The only other truly spinach-y type thing I can grow well at all seems to be New Zealand Spinach, which actually is from an entirely different plant family. Not complaining though because I think I actually like it better!

Check out the entire subfamily: https://en.wikipedia.org/wiki/Chenopodioideae
These guys are really good in high salinity and alkalinity soil https://en.wikipedia.org/wiki/Atriplex
Callaloo aka Amaranth (green or red leaf)

Rudyard Blake wrote:

S Bengi wrote:heat loving plants from the spinach family

What heat-loving spinach relatives do you recommend? I am trying to grow chard, as it's supposedly a little bit drought tolerant, but it doesn't seem to like the heat and is very wilty, even in the shade. I have some amaranth too, which does fairly well, although it needs a lot of watering before it gets going.

The only other truly spinach-y type thing I can grow well at all seems to be New Zealand Spinach, which actually is from an entirely different plant family. Not complaining though because I think I actually like it better!

Check out the entire subfamily: https://en.wikipedia.org/wiki/Chenopodioideae
These guys are really good in high salinity and alkalinity soil https://en.wikipedia.org/wiki/Atriplex
Callaloo aka Amaranth (green or red leaf)
https://en.wikipedia.org/wiki/Callaloo#/media/File:Palmer_Amaranth_in_the_Field_(9623963758).jpg