I didn’t have much plans to grow zucchini / summer squash. I prefer to eat the more dense flesh of unripe moschatas, ie. Zuchetta.
This year zucchini are growing better for me than expected in a challenging soil. I do like to grow things that grow well, and I’m not growing the fruit for my own consumption anyway, so I might as well start tracking this project now.
So far I’m just selecting for ease of growing in this site. I need to figure out some kind of labelling system if we’re going to harvest a fruit, cook with it, do a taste evaluation, and then select plants to grow for seed.
Last year I planted out a few hundred cucurbits with no water at a pretty free-draining site. Luckily some rain in the beginning. Then summer had a 1,5 month drought with very little rain. Of all those plants, I only got one fruit - from a zucchini plant.
I call it the 2024 Lejre Survivor and found it very special.
This season 2025 I used that seed combined with previous year’s seed, incl. some worty Rugosa Friulana-types, the Croatian grex and the French PEPS grex. I direct sowed all plants on 30m2 very late 17th June in one of the last beds.
Some pics of the diversity of fruit that I will let go to seed
I have plenty of seeds from last years survivors if you’d like some. This year they didn’t do as well, which might be from lack of nutrients. We’ll see next year how it goes. Did get some from my regular plot, but with the dry and not watering enough they didn’t do that much more than just the big fruits for seed. I think one trait to look for is smaller mature fruits so that it’s possible to leave them for seed without them stopping to produce that easily. Had some closer to that in my original crosses, but haven’t had quite like that this or last year.
Yes, I’d like to include those next year. I’ll pm you about seeds.
As for size of fruit at maturity, is that an assumption or something we have evidence of? I’m intrigued. I also wonder if smaller mature fruit would affect the speed at which the fruits grow.
Yes, they generally put first energy to grow the first to develop and others depending on how much they are fed and watered. With good watering they can produce unaffected even with huge fruit developing, but they easily stop producing if watering isn’t sufficient. Ofcourse smaller mature fruits are strongly correlated with smaller immature fruits. Yield might be lower at least in kg and you need to pick them smaller and more to get decent yields. But bigger fruits might loose some in taste also. I had F1 of small round and normal yellow that made mature fruits around 1,5-2kg. I should have some of those F2s at least. This year I had more from others aswell to increase diversity and some have mature fruits probably closer to 10kg and it seems common that they are around 5kg.
One added trait could be hulless seeds also. I have abstained from growing oil seed pumpkins because the yield of seeds is fairly small and I just get more pumpkin I can use. Plus it would hard to keep them separate from summer squash. But as a combination it might work, even if I tend to oversow quite a bit at this stage.
I have a round one that i immediately have let go to seed, it produced little after. And the one that had 12 yellow/green baby courgettes on it at one point stopped producing when the heatwave without rain came. Then they kind of rotted from the end and only two big ones got left, that i left to go for seeds. But one split open, so i took it off. Now that rains have returned, the flowers are back on and courgette flow turned back on..
Jesse when you speak of selecting for early maturing ones, i take it you mean that you want that they earlier throw seeds in the smaller courgette. Would that mean that they keep producing new ones? Because they have more energy left… But if they have all those seeds in a small courgette, they might burst… Should we not select for courgettes with fewer seeds as well in that case?
I think this is a very interesting option. What I hear the two of you proposing is to breed zucchini that tends to make smaller seed fruit and continues to produce while one fruit is maturing. Has no one done this before?
I think I had one variety in my grex last year that had this - one big fruit that I left for seed, and then 2 more to harvest. I think it was Genovese variety.
I just put seeds of my zucchini grex to dry. Despite the draught I was able to collect one fruit of each plant that was growing during the june-July heat wave. I had 12 of those, and then I added the seeds of the second generation, and now more are growing. They had no watering at all in clay soil, all direct seeded. So I will have plenty of seeds for next season.
Maybe one of the experiments could be what you are suggesting now that I have seeds with more to come.
I don’t know if this will help, but my experience.
I grew zucchini dry a few years ago, unknown variety. Soil was almost straight sand. No rain. Temperatures consistently upwards of 95 F (35 C) and often higher. I gave them 1 gallon of water when I put seeds in the ground. I watered about once a month, so not completely dry.
Each time I watered, a flush of 6-10 zucchini grew. They matured small and quickly, with mature seeds within a few weeks if I left them on the plant. If taken off, the plant continued to flourish but put out no blossoms until the next time it was watered. When the “seed” zucchini were harvested, the same pattern continued next time I watered.
I assume this behavior is because of extreme environmental stress, but it does show that it’s possible.
I don’t think I said selecting early maturing. Not sure if I have alluded to that in some other post. It’s true that early maturing is goal in most what I grow, but summer squash isn’t a problem. They can mature fairly easily just about any year. Only problem has been in survivor plot, but there they have maybe too many challenges to overcome. I’m more focused on getting them to produce immature fruits to eat as early as possible. Ofcourse that is somewhat correlated with early maturity. In terms of maturity from flower I don’t care if it takes a week more (unlike with melons etc) they are still fast enough. Like this year I picked first fruits to eat and only let them make fruits for seed late july/early august.
My goal is to have many small courgettes that i pick off when they are as big as a finger or a bit longer. That’s what the French like and i like the baby’s because i can put them uncooked in salads. The salads look a bit more interesting that way.
But then i was gone and some got really big and i decided to keep those for seeds. Stupid. They stopped caring about producing new fruit. Off course they only care about that one big fruit and all energy goes into that one big promising fruit. It takes a long time for seeds to get to a weight that is viable to produce new plants next year. If you pick them halfway, thinking the seed will be good, or if one splits open from sudden rain and dry the seeds, they shrink into skinny fake seeds when i dried them, if you know what i mean.
What i am trying to say is that it would be nice if my above thinking is right, that i would like it that i could have courgettes that do not have this ‘let’s put all the energy in one fruit’ mentality..
So i thought it would be good to have courgettes that have less seeds in a not giant fruit, so they can keep producing little courgettes, drought or not.
But all that idea goes away if i just do like you and pick them until the end.
Communication to really say what we want seems difficult sometimes? Or is it just me. That we to know what the other means and then come with a reply, but they didn’t mean it at all and then get some more confusion in the answers…
I try to repeat back to show i understand what the other says first. But a word like maturing, what is maturing? Plant maturing to produce flowers or flower maturing to produce a fruit or fruit maturing to produce seed that isn’t mature yet, or a fruit that produces viable seeds.
Is it just me struggling with this sometimes? Is there a way to get over this problem, because if we cannot share ideas clearly… we cannot move on together.
You’re not the only one, I struggle with it too a lot of the times. Losing the point, trying to understand something that’s ambiguous or can be interpreted in several ways. I find it especially difficult over text, because neither party can correct the other mid-sentence, if they got lost. Text can make us go into exchanges of long monologues. And you’re right, if the point doesn’t get across, we’re not using each other’s resources to build on top of each other.
for me English is easier in writing/reading, but you are right about the fact that writing can leave misunderstandings especially when it isn’t our mother language.
that’s why it’s important to see and speak with each other in real life once a year and move on together…
Yes and that’s a shame, because when you have to write your thoughts down, more often it takes more time to type and you can really try to get a point across then when speaking. Although speaking together like Stephane is saying is also really good, because then you have facial expression and you can interupt and ask questions easier.
i hope we will develop our own breeders jargon when we advance on our adaptation journey.
Thank you for your honesty. For nerds (which we all are here) it’s sometimes difficult to admit we don’t know things, that also hinders progress, but it is deserving of a topic in itself. So i stop derailing the topic!
in 2026 I try the following kousa type from the South, because this summer the zucchini were not very productive… only 2/3 fruit per plant.
does anyone have feedback (in hot or cold countries) with the kousa type ?
I will try again the following variety which is supposedly the most ugly but the best in terms of taste. This year the plants produced nothing, they just burned before the fruits.
would I try to integrate all them with a mega grex of zucchini to see what comes out?
I have a fruiting Rugosa friuliana this year that I expect will mature to seed. Although strangely last year when I got a mature fruit from @Logan it had no seed inside even if it was hard as a stone on the outside.
Ok, I understand. I just took it literally what you said. You could use early flowering/producing (since immature fruit is the harvest)/fruiting. Early maturing would refer to fruits ripening to their full ripeness.
If your concern is that the fruit takes longer to mature and thus slows down production of immature fruits, then it would be advantage to have them mature faster from flower. Selecting for that isn’t as easy as they can be affected by weather conditions. One might speed up maturation because it’s more stressed than other, but that’s not really a good thing. Similarly size could be affected by weather conditions, but that might be still more reliable overall. Amount of seeds I don’t think affect that much the time it takes for the fruits to mature from flower. All seeds mature around the same time (unless there is some stress) and it’s not like it can put more energy to develop others if it has less seeds. Also it develops flesh to maturity. I would say small fruits and several vines that can easily root from the leaf nodes (and thus be more independent) would be the way to go.
I have some 600m2 of something similar growing on the neighbouring plot by immigrants from middle east. I have taken some pollen to pollinate what I grew and bumble bees might have done the same as there is only a few meters between. I assume it must have been cross with that type that were the ones that survived on the survivor plot last year. One of the first years they didn’t water, but the plants kept producing. Lately they have also watered, although the amounts for that kinda area might not be as much as summer squash generally requires.
600m² of zucchini ? for sure there is a strong chance that your garden received pollen
These kousa look interesting in dry conditions but visibly also in the north for their ability to continue producing fruit.
My zucchinis were more in survival mode with the hot weather and drought this summer. The leaves never went down but the fruits aborted… can also be linked to the fact that the bumblebees were under stress and rather absent.
