Squash plants of all varieties--from patty pans, zucchini and crookneck to acorn, butternut and spaghetti--all benefit from fertilizers and organic soil amendments. Well fed and supported squash plants will develop healthy fruit more quickly. Synthetic and organic fertilizers can be used on their own or in tandem support healthy growth and bountiful harvests.
Complete Synthetic Fertilizer
Apply a complete garden fertilizer with a guaranteed analysis of something like 10-30-10. Stagger the feedings throughout the growing season but not exceeding three pounds of fertilizer per 100 square feet in one year. Apply half of the fertilizer to the soil during planting in a trough offset from the seeds by three inches. Make the next application one month later.
Organic Soil Fertilizer Amendments
Fruits like squash respond well to organic amendments to enrich the soil both at planting time and as topdressing or mulch. Blend in a few pounds each of well-aged livestock manure and compost to the bed scratching into the soil surface and watering in well to leach the nutrients into the soil.
Late-Season Nitrogen Boosting
A high-nitrogen organic fertilizer formula such as 13-12-2 guano blend can be fed to the soil around your squash plants at the onset of harvest when the squash are ripening. This will "supercharge" the plants to remain vigorous and keep producing squash into the next season.