Growing squash from seed is so easy that there is no point in buying seedlings unless you just don’t want to plant seeds. Squash are easy for two reasons:
1. The germination of rate of the seeds is high
2. The germination time of the seeds is very quick (about 1 week)
From this we can conclude that:
1. There is little risk in trying seeds as most will germinate with little trouble
2. The usual advantage of buying seedlings (getting a jump on the season) is only one week. Because you can produce seedlings from seed in about a week you can germinate them on a window sill about 1-2 weeks before the weather permits you to plant them outside in the garden and the seedlings will not become elongated and weak from lack of light in that week or two.
3. Or you can plant the seeds directly in the garden once the soil warms up and you will only be a week behind the squash started indoors by yourself or a vendor.
I also like the idea that I can buy a package of seed, use about 2/3 for my first crop and still have enough seeds to plant later in the summer so that I can have summer squash through out the summer, into fall. Buying seedlings in mid summer for that second crop is not easy, perhaps impossible as most retailers carry seedling about the time they can be planted in the garden and quit long before the squash quit producing squash in your garden.
I hope that I have convinced you to try growing squash from seeds and that you have selected the varieties you want to try. Whether you have seeds or seedling the process is essentially the same. Prepare the bed by digging deeply and adding an all purpose fertilizer several weeks before you plan to plant the seeds or seedlings. Wait until after the last frost and the soil is warm and then plant 2-3seedlings or 3-5 seeds in circles 4’-5’ apart. Plant the seeds 1” deep. When the plants have their first true leaves (the second set) thin to two plants per circle, removing the weaker ones.
Squash need large amounts of water and nutrients so you will need to water and apply fertilizer frequently. The large and dense foliage can make this difficult so sink a 1-3 gallon pot, perforated can or milk container next to each pair of squash when you plant them. Water and water soluble fertilizer can then be applied together easily as needed. Water the squash at least twice a week and fertilize once a month as soon as the first fruit are set and then use a fertilizer that has high phosphorus (middle number) to stimulate flower and fruit development. Avoid using a high nitrogen fertilizer especially before flower formation because you will encourage the growth of lots of leaves at the expense of flowers and fruits(squash). Mulch to conserve moisture. If mildew forms, avoid overhead watering. Most insect pests can be controlled by Sevin if necessary.
Harvest squash when young and small! Summer squash should be harvested when about 6”-8” long and no bigger than 2” in diameter. You really can’t harvest them too young. You should check your summer squash crop daily as one day can make a huge difference in the size of a summer squash and make it unusable. If a summer squash gets large check the tenderness of the skin and discard those into which you cannot easily sink your fingernail. Pick and throw away the ones that are tough because they will suck energy from the plant if you leave them on it. The leaves and stems are prickly and may irritate your hands and arms so wear gloves if this is a problem. Use a sharp knife or shears to cut the squash from the vines so that you don’t harm the fruit or plant. Handle the newly harvested squash carefully so that you don’t damage the tender skins. Store squash unwashed in plastic bags in the crisper of your refrigerator or up to 4-5 days. Avoid washing before using them because water on the squash will promote decay.
You can also harvest the male and female flowers (the latter may have small fruit attached) for a tasty treat Italian style. Use a sharp knife or clippers to cut the blossoms at mid-day when the petals are open. You can harvest most of the male flowers without significantly hurting squash production but harvesting the female flowers will lower it. To distinguish the genders examine the stems of the flowers; the male flowers have thinner stems than those of the female flowers and the latter has a small bulge (the developing squash) at its base. Wash the blossoms in cool water and store in ice water in the refrigerator for up to a day or two.
Winter squash are harvested in much the same way except for the hardness of the skin and the size issues. Winter squash grow more slowly than summer squash and will reach maturity later. They are harvested when the skin is hard and can be left on the vines until the first frost and the vines are dry. Winter squash blossoms can be harvested and eaten exactly as those of summer squash.
If you are growing squash this summer you are in for a lot of good eating and you will probably have many to give away.