What went wrong?

[AshyLlama12]

I bought some zucchini and yellow squash from a local nursery in April and initially they were doing good. Very green, lots of male flowers but something’s seems to have gone wrong. I would see some female flowers start up but never get to the point of developing a flower before dying off. Now the color is fading, growth and flowers have stopped and they just look wrong.

I have quality soil and compost and water regularly. I thought maybe it was the temperature? Mid to high 90’s everyday.

I thought zucchini was supposed to be an easy crop but I’ve messed that up somewhere along the way. I’m not sure the temperature will allow for a summer crop if I try to start over but I can try again the fall but I’d like to know if anyone knows where I went wrong?

 

[Chuck]

Have you fertilized and if so with what?

 

[AshyLlama12]

I have not, they’ve only been potted for a month-ish. I didn’t think it would be time for fertilizer yet. I could go get some general purpose veggie fertilizer and see if that helps.

 

[Meadowlark]

I have not, they’ve only been potted for a month-ish. I didn’t think it would be time for fertilizer yet. I could go get some general purpose veggie fertilizer and see if that helps.

It probably will not make one cent of difference.

Above 90 deg F, zucchini does not do well, and in fact often withers and dies. Most all of Texas has been above 90 deg F for several days now...my own zucchini just bit the dust.

The combination of very high temps (above 90 deg) and high rainfall is not conducive to zucchini growth or even survival. You likely did absolutely nothing wrong...the weather is tough right now.

 

[Chuck]

My yellow squash is doing OK and I planted a little late. I get one or two per day off of 2 plants. The pictures show yellowing on many leaves and even the green leaves are too light of a green color, the result of not enough nitrogen. Thus the question about fertilizer. I fertilize my containerized -squash when the plant has 2 sets of true leaves. I haven't had near the amount of rain as @Meadowlark has had and today is the first day above 95F but have had many days of 90+. I generally have poor production and plant growth when temps are above 95. Fertilize!

 

[cpp gardener]

I'm with Chuck. Around here we regularly get temps over 100 and can't keep up with squashes of any kind. How often is 'watering regularly' ? I would think in a pot that small it would be every other day if not daily. A much bigger pot might be better.

 

[Galatians 5:22]

I bought some zucchini and yellow squash from a local nursery in April and initially they were doing good. Very green, lots of male flowers but something’s seems to have gone wrong. I would see some female flowers start up but never get to the point of developing a flower before dying off. Now the color is fading, growth and flowers have stopped and they just look wrong.

I have quality soil and compost and water regularly. I thought maybe it was the temperature? Mid to high 90’s everyday.

I thought zucchini was supposed to be an easy crop but I’ve messed that up somewhere along the way. I’m not sure the temperature will allow for a summer crop if I try to start over but I can try again the fall but I’d like to know if anyone knows where I went wrong?

Since they are in containers, I would move them to a spot that has shade during the hottest part of the day. Squash plants will wilt temporarily in the heat, but they should survive 95 degree weather anyway and come back looking good in the evenings and mornings.

The soil looks super dry. I would mulch with a light colored mulch like straw (or dried grass clippings). This reflects the heat and helps keep the soil moist and cool. Then water to soak all the way down.

For me when squash plants are healthy and then all of a sudden get sick, it is usually the Wine Borer. It goes into the stem and puts larvae in there that eat up the inside of the stem so that the plants can't get any neutrients. If that is the case, you will see some "shavings" of the inside of the stem laying on the ground right next to the base of the stem. It is very hard to recover plants from this pest.

If you buy new plants, and plant them now, they should be safe from the wine borer since it is past its egg laying time now in the season (or wait another couple of weeks to be more sure).

If you are using potting mix I would also fertalize weekly.

Hoping this helps (just an enthusiast sharing some of my experiences here). There is IMO something happening here more than just heat. The heat could have made them weak and then more prone to suffer from pest or decease.

 

[Meadowlark]

I'm with Chuck. Around here we regularly get temps over 100 and can't keep up with squashes of any kind.

Maybe, but most places, most growers experience says above 90 deg. and zucchini starts showing signs of stress as described by the Op.

I've been growing it for decades and have never seen it produce "can't keep up with squashes" at temps over 100 deg. F as claimed by the above poster...but in gardening anything is possible, but not necessarily probable.

A quick search confirms my own experience that 90 deg F is about the upper end for stress free Zucchini:


The ideal temperature range for zucchini cultivation is between 70°F (21°C) and 90°F (32°C).

What Temperature Can Zucchini Tolerate? Understanding the Temperature Range for Zucchini Growth and Survival - Happiness Zucchini



The ideal temperature range for growing zucchini is between 65-95°F (18.3-35°C). Cold weather will quickly kill them, and high heat will lead to wilting and possible sunburn on the leaves and exposed fruits.



Growing Zucchini - The Complete How To Guide - Get Busy Gardening



The ideal temperature for zucchini growth is around 75-80 degrees Fahrenheit. If temperatures exceed 85 degrees, however, zucchini plants may start to suffer from heat stress.



How Much Heat Can Zucchini Take? Understanding The Temperature Tolerance Of Zucchini Plants | ShunCy



Hot weather over 90°F can prevent flowers.



When to Grow Zucchini in Texas: A Complete Guide - GreenThumbsGuide

​

@AshyLlama12, I hope you will report back on whether or not fertilizing solved your problem...and also report back when temps regularly get over 100 deg F on how well your zucchini produces...and if it does indeed produce "can't keep up with squashes" amounts over 100 deg, I will have certainly learned something.

 

[big rockpile]

It probably will not make one cent of difference.

Above 90 deg F, zucchini does not do well, and in fact often withers and dies. Most all of Texas has been above 90 deg F for several days now...my own zucchini just bit the dust.

The combination of very high temps (above 90 deg) and high rainfall is not conducive to zucchini growth or even survival. You likely did absolutely nothing wrong...the weather is tough right now.

Your full of good news.

I have 3 Zucchini just sprouting and next few days above 90F.

big rockpile

 

[Bleeckerclerk]

Zucchini in pots that small get root bound very quickly, and high temps affect them much more. If you can't plant in larger areas, moving them to the shade might help.