I planted 3 varieties of squash this year from Walmart--they were labelled spaghetti, crookneck and zucchini. Most are doing well with lots of flowers and starting to bear fruit (my first spaghetti squash is on the vine!). Three of the plants developed into very large bush plants with giant leaves on long stems BUT they have not produced any flowers or fruit. Can't figure out what is going on since they get same care as others. Don't know what to do since it is mid summer now. The plants look very happy with healthy green foliage, but if there is no hope for any production, should I pull out so surrounding plants can benefit? Could these plants be something else for which there is still hope?
What to Do With a Giant Bush Squash With No Flowers
Certified GKH Gardening Expert
They are getting too much nitrogen. This causes large amounts of leaf growth but little to no flowers. If they are all located in the same spot, there may have been a pocket of nitrogen heavy amendment in that spot, maybe from manure that was not thoroughly worked into the soil.
You can try giving them some phosphorous rich fertilizer, which will help balance out the soil again. Bone meal is the common amendment for this, but may not be able to release its phosphorous fast enough to help you with getting these annuals to produce before they die, so you may need to look to chemical fertilizers.