Taraleigh, I am not going to fool with mine. I will harvest what I can and then plant something else. The quality is dropping and the insects are getting more hungry. I have one more head that I may be able to salvage. My red cabbage did not do well at all. The broccoli plants are not far behind. The broccoli has been good but the heat and insects ate taking its toll on it also.

You may be able to save your's but I will be investing my space in something else.

Larry

Tara,

I was torn between whether to give you the quick and easy practical answer, or the longer and more detailed explanation that might help you baby the plants along for a few more weeks. So, here's both:

QUICK & EASY ANSWER: Extreme heat has set in this week and the cabbage plants aren't going to like it. You can try to keep them growing a bit longer by shading them. Be sure you let them have 3-4 hours of early morning sun and then full to dappled shade the rest of the day. Keep them well-mulched. You may or may not succeed in this effort. It is hard to say because the plants likely have had a lot of heat already.

MORE IN-DEPTH ANSWER:

This is a hard question to answer without knowing how much hot air and high soil temperatures the plants already have endured.

In general, shading cool season plants will help extend their life a little bit, but it would have worked better for the cabbage if you'd begun shading them before your high temperatures starting exceeding about 75 degrees. When you wait until the temperatures are approaching 90 degrees, the cabbages likely already have had a lot of exposure to temperatures they don't particularly like. At this point, you might as well try shading them if you can. It won't hurt them, and still might help them---but not if they've already had too much heat.

If I was trying to shade cabbage plants this late in the season, I'd let them have exposure to full sun only until about 10 a.m. Here at our house today, it already was 85 degrees by 10 a.m., so if I was trying to keep cabbage plants alive and growing with partial shade, they likely would have been whining and hollering for the shade by 9 a.m.....but you have to let them have 3 or 4 hours of sun at a minimum so they'll keep growing and form heads, if they can, in this heat.

You can use shade cloth, commonly sold at nurseries and in the garden centers of big box stores. Often it is custom-cut for you and comes on big bolts and priced by the running foot. The first shade cloth I ever bought was folded and sold in a flat pack. I believe it was 6' wide x 50' long and I bought it at Sam's Club quite a few years back. Shade Clothe comes in different weaves that allow different amounts of light penetration--I use 50% shade cloth on the greenhouse and 40% shade cloth in the garden for heat-sensitive plants. If you just want to experiment with shading without spending money on shade cloth, you can use an old bed sheet or sheer to semi-sheer curtain.

In future years, if you want to use shading to prolong a cool-season crop, start using the shading when temperatures are a little under 80 degrees in order to keep the plants a little cooler.

It also helps the plants a lot if their soil is well-mulched. Garden soil that has 2 to 4" (or more) of good thick dense mulch on top of it can easily stay 20 to 30 degrees cooler, or sometimes even 40 degrees cooler, than unmulched soil in full sun. I was working in a new garden plot in very late April and early May, trying to finish the fencing, put up the trellises, etc. and get planting done. Obviously, nothing was mulched yet since we were barely getting plants in the ground. On one unseasonably hot day as I was transplanting cucumber plants into the ground, our soil temperature was so hot that it was unpleasant to touch the soil with a bare hand. As soon as I finished planting that day, I cut the lawn grass and used the clippings to mulch the planted portions of the garden. Now, every time we mow, I layer new grass clippings on top of the old. Our older, established garden already was mulched well-enough before we started working on the new garden plot, so this year, the new garden is getting most of the grass clipping mulch. By the time soil temperatures are exceeding 100 degrees here, I should have mulch on the ground thick enough to keep the soil about 20-30 degrees cooler than the air temp.

Cabbage is a cool season crop and is happiest when the daytime highs are in the 60s, which is why we need to plant it about 4-6 (or even 8) weeks before the date of our average last frost.

As you have undoubtedly noticed, we often go from 'too cold' to 'too hot' practically overnight here, which makes it tricky to get a good yield from cool-season crops. Planting them early is the key. The later you plant, the harder it will be to get a good yield. However, if we plant too early, the cold can cause them to bolt...so it is challenging. You have the extra challenge of having a precious child who destroyed your seedlings. It happens. Pets, children, etc. can be hard on our plants. I always raise extra from seed and try (not always successfully since cats can jump and climb) to keep them out of the reach of anyone who might accidentally destroy them.

The good news is that with shading and mulching, cabbage seems to tolerate more heat than you'd expect. However, by heat, I mean maybe temperatures creeping into the low 80s, and not so much the low 90s.

DIfferent varieties tolerate heat at different levels. I always try to choose varieties known for their heat tolerance and that have fairly short DTMs. Even then, sometimes the heat just arrives too early. Some years I have had cabbage happily tolerate a lot of heat in June. Other years, it has caused the heads to get puffy or the plants to begin splitting in order to send up a stem to flower. I usually plant far more cabbage than we need and start harvesting small heads in March. As the season goes on, we are harvesting and eating progressively larger heads up to a point. Then, when the heat arrives, I tend to harvest them on the small side again to get them out of the heat.

This year has been a mixed bag of results. Some plants formed heads pretty early and were harvested early. Some were slow to form heads. Some didn't form heads at it. At our house, what do we say about such uneven results? Of course, we blame them on the weather, but we also just shrug and say "it is one of those years".

Since the stonehead already has headed up, I'd go ahead and harvest it and use it. High temperatures can make cabbage go downhill fast and sometimes affect its flavor. I'd shade the Bonnie hybrid and try to baby it along for a few more weeks so it gets at least a fighting chance to make the head it is trying to form. The red types in general are slower than the green types to form heads. This year I had full-sized green heads while the red varieties were just sitting there in their leafy glory. They did finally head up too but it seemed to take forever, even though, according to their DTMs, they should have been heading up at the same time as some of the green varieties. I just think the reds are more stubborn. Reds grow great in fall, as do all cabbages, but you have to transplant young cabbage seedlings into the ground in August in order to get heads before really cold temperatures set in. If your red cabbage doesn't start trying to form a head in the next 7-10 days, it likely won't form one because the heat will just be too much for it, even with shading.

Hope this helps,

Dawn

Thank you so much Larry and Dawn!

I went ahead and pulled the stonehead. I'm going to try and nurse the others along like you said. They were put in mid March, I thought it was early enough. I used milk jugs to protect when we got in the mid to low 20s, and they've been consistently watered by me or mother nature. They are mulched, but I think my entire garden could use more. I used an old bedsheet starting a few days ago to give them shade after 10, then a bit of evening sun until shaded by the house, but only 30 min or so. We'll see how it goes. There isn't anything going in right after the cabbage, so no rush to pull them out. If they don't head up in the next few weeks, but haven't sent up their flower, are the loose leaves edible or not? We mostly wanted to make cole slaw with these first cabbages.

And I'm definitely trying again in the fall. I've barricaded my dining room off so the dogs and the baby can't get to the seedlings, and put them up on shelves if they break through the barricade. I'm hoping I won't have to rely on purchased transplants this fall.

Thanks again!

Tara great question about the cabbage leaves.
Boiled enough I wonder if I could make cabbage rolls and use my tiny heads for slaw. Ever find out?
Tree

Not really. My red cabbage never did make a head, but my husband used the innermost flat leaves and cooked them in a pan with some other veggies. He just cut them like he was making slaw. He liked it all right. My green ended up making smallish heads, so we just used those and put the leaves in the compost pile.