The summer squash include patty pan, yellow crookneck, and zucchini. These squash will cross pollinate with other summer squash varieties but not with other squash species (for example winter squash like butternut), and will not cross with other genera like cucumbers or melons. To keep strains pure for the purpose of collecting seed, plant varieties 500 feet apart or grow only one variety a year. If crosses do occur the resulting seed will probably produce fruit of lesser quality but it will still be edible. Avoid hybrids and use open pollinated seeds if you want to collect seed for the next year.
Summer squash are warm weather plants and do not transplant well. They can be planted outdoors about a week after the last frost but can be started indoors using one of two methods.
Directions for Outdoors Planting:
1. Plant seed in compost amended either hills three to four feet apart or rows three to four feet apart. Use six to eight seeds per hill or space seeds four to eight apart in rows.
2. Keep evenly moist but not wet. Germination occurs in seven to ten days under optimal conditions.
3. Thin plants in hills to three plants per hill and to fifteen inches apart in rows. Snip unwanted seedlings from the row rather than pull them so as not to disturb the roots of nearby plants.
Directions for Indoor Planting in Peat Pots:
1. Three weeks before the last frost plant seeds ½ to 1” deep in peat pots, one seed/pot.
2. Place in an area with temperatures between 70 and 95 F and keep moist but not wet. Germination occurs within seven to ten days under optimal conditions.
3. Harden off and plant out in the garden about a week after the last frost. See Directions for Outdoors Planting step 1 for spacing.
Directions for Indoor Presprouting:
1. About a week before the last frost wrap seeds in moist paper towels and enclose in plastic bag.
2. Put in a warm area (70-95 F) until seeds germinate (seven to ten days)
3. Plant in garden bed as directed in directions above. Once seed has sprouted they can grow at lower temperatures than needed for germination.