I have only had moderate success growing zucchini on my terrace. The first time I tried, I had four gorgeous plants that grew so quickly that I was obliged to go out and buy larger planters as even a novice zucchini grower like me could see that they were stifling in the small narrow planters. It's true I grew up in the Midwest and helped my mother and grandmothers in their vegetable gardens every summer, but it had been 15 years since I'd personally seen how large a zucchini plant can grow (answer=very). So the first batch of plants had lots of foilage with many beautiful flowers, followed by a few misshapen fruit, skinny and wrinkled on one end and round and glossy on the other.
When we moved into our new home in the 17th, I planted them in a much deeper square planter and awaited with great anticipation some nice big zucchini. Again, I had lots of big healthy leaves, loads of flowers and then...they just withered away. Before you can ask, yes I was watering them daily so it didn't seem to be a drought related problem.
Fast-forward to this year. I dragged the deep planter to the sunniest corner of the terrace. Previously, they had been in a more convenient spot in terms of traffic on the terrace, under the eaves of the roof. So I worked on the theory that on our Northwest-facing terrace the plants would need some help getting enough sunshine.
Please excuse the long-winded history of zucchini growing. I'm getting to the point.
It seems to be working: loads of big green leaves, loads of flowers and loads of zucchini. BUT. If you look a little closer in the photo, you'll see that the two vegetables closest to the camera are looking fine, just about large enough to harvest and very healthy. But some of the ones lower down are all wrinkled and unhealthy looking. Should I harvest the entire lot of zucchini, healthy and unhealthy and hope that it will flower and fruit again? I gave it a little worm tea (liquid fertiliser from my wormery) earlier in the summer; does it need more? Or more water? Should I have pruned back to only two or three zucchinis earlier in the season, on the basis that a plant can only support so many vegetables at once?
Let the experienced gardeners out there please come forward and guide me; I find it embarrassing that the one plant that my grandmother and mother grew to over-abundance with no effort at all is escaping me!
(Oh and if you have any advice on getting spinach to grow to a decent size - i.e. more than four leaves - before bolting that would be most welcome too. *sigh*)