Eggplants like warm, even hot temperatures. They begin to thrive when daytime lows reach 70 F. and beyond, and when nighttime temperatures finally climb out of the 50s. When you notice that daytime temperatures are becoming consistently warm for days on end, it will be time to set your eggplants into the ground.
Because of our cold spring nights, it's not the best idea to plant seeds directly into the garden. If you want to grow eggplant from seed, you'll need to start them indoors or in a heated greenhouse. If you do plant from seed, soak the seeds overnight before planting them in a well drained, somewhat sandy potting mix. Four inch peat pots work pretty well. Plant them close to the surface, between 1/4 and 1/2 inch deep. You'll need to keep the seeds moist and the soil temperature warm. It takes eggplant seeds a week or so to germinate.
Eggplants need the entire growing season to produce well (between 3 and 4 months of good summer-like weather), so starting seeds early or buying nice, healthy seedlings is the way to go. When it's time to plant the seedlings, give them plenty of growing room (1 1/2 to 2 feet apart) in a place that receives full sun. The plants can get rather large and they seem to enjoy space between themselves and other plants. If you are to plant them in rows, space the rows at least 2 feet apart as well. Be careful with their delicate little root balls, as they are known to be susceptible to plant shock, and help them acclimate to the outdoors with a few days of hardening-off.
Once well established and growing big, you can stake eggplants to help support their sometimes large, heavy fruit. You can even cage them like tomatoes, but usually a single stake to support the main stem will suffice. Eggplants also do very well in containers at least 12 inches in diameter. You might want to cover the top of the soil with a prepared organic mulch. This is especially the case with container gardening in high desert and mountain environments because plants in pots have the tendency to dry out faster than they do when in the ground. (You can prepare your own mulch from year to year. We also offer very high quality organic mulch at our garden shops.)
The soil needs to be rich and well draining. Offer them what you would expect to offer typical food producing plants. Give the potting soil a good dose of organic compost. During the heat of the summer and periodically throughout the growing season, give your plants a controlled shot of organic fertilizer. (We offer organic fertilizers. Come in and talk to us about how to properly fertilize your garden vegetables). From year to year, it's a good idea to rotate the same soil with other vegetables.
You'll want to pick the fruit when it's beautifully eatable. That is, firm, healthy, with a satin sheen and big enough to be usable in recipes, but not too mature. You don't want to let them get old and hard (and ultimately bitter).
When the season is nearing its end, you can make sure your plants concentrate their remaining fruit producing energies on the fruit already present. When you start to feel the autumn harvest approaching -- somewhere between two and four weeks before the picking time -- you can gently begin the anticipatory task of nipping off newly appearing buds. The plant will quietly panic and respond by focusing its efforts on what fruit is actually already in the works. A final prefrost harvest of nice sized, beautiful fruit is the intended result. Once the frost hits, the eggplants will die. If any fruit remains on the plants, check to see if they are still shinny and if they feel nice and firm, but not overly dry, hard or even overly soft with shriveled skin. If the remaining fruit has passed its prime, pick it, then throw a banquet for the earthworms at the local compost pile. They will love you for it, especially if the fruit is squishy. If the fruit is hard, just bury it under the surface, water it and in no time the frost bitten fruit will be your every worm's delight.
