Keep the fresh vegetables on the table this October with a late summer planting of cool season crops. Now is the time to get the last of those seeds in the ground and extend your food production over the next few months. With our warm temperatures this month, seeds will germinate quickly. The optimum temperature for seeds to sprout is usually between 65 and 75 degrees F. How often do we get those numbers in the spring when we sow our first crops? Rarely. So, take advantage of this seed sprouting weather and sow some cool weather crops. But which plants to grow? To have success, try plants grown for their leafy greens rather than big juicy fruits. Cool season veggies include leaf lettuce, cabbage, kale, cauliflower, broccoli, spinach, mustard greens and brussel sprouts.
Two numbers are important in fall gardening; the average date of the first frost and the number of days to maturity for each crop. For the Seattle area the average first frost date is November 11th. This sounds right, remember our freezing week in November 2010 that killed off many a bud and leaf? It was a quick change from warmer temperatures and many plants didn’t have time to harden off and prepare for the cold. That’s a one way ticket to the compost pile for some species. So if seeds are planted now, at the end of August, they need to mature in just over 60 days.
Here is a look at some of my seed packets from this year. Bunching onions or green onions are 75 days to maturity. Too long it seems, but the instructions say these will overwinter for a spring harvest, or young onions can be snipped and used like chives. Remember to add one to two weeks to the maturity date to factor in the slower growth of plants during the cool, shorter days of autumn. Leaf lettuce seems to be a good bet for fall planting, since it grows best in cool weather. My Red Leaf Lettuce matures in 50 days and the Romaine takes 65 days, but lettuce is still delicious and tender if harvested early. Swiss Chard takes 55 days to maturity my Ed Hume packet instructs, but this year my chard seemed to take forever (I planted it in May and still haven’t picked it). Carrots take 75 days, so it is probably too late now, but if planted by mid-July, they can be harvested in the fall, or even survive the winter for a spring harvest. Peas are 68 days to maturity and spinach takes 46 days. If you like that spicy crunch of a fresh radish you’re in luck, they can mature in only 30 days! It seems that a salad garden is the order of the day for fall gardening. As autumn turns towards winter, cold frames and cloches can protect plants and extend the harvest even longer. Don’t pack away the shovels just yet, we still have months of fun yet to dig in the dirt!