How to prepare your SW WA garden for the fall

Fall seems like a distant thought, right?

Especially with our long, warm autumns, you might enjoy those summer veggies well into October or November, especially if there’s no hard frost.

But here’s the scoop: fall is the prime time for many plants, especially those that thrive in cooler weather and actually get sweeter with a touch of frost. So, if your spring broccoli or cabbage bolted early or tasted bitter, fall planting is your chance for a fresh start.

No room left in your garden? Sure there is!

Garlic and onions will be ready to harvest this month, so you’ll find additional space for fall crops. Many of your spring veggies, such as early peas, lettuce, radishes and other salad are done for the season.

Are some of your tomatoes or zucchinis not doing well, or did you plant more than you need or want? This is another opportunity to create space for your fall garden plants.

Add compost and organic fertilizer to replenish nutrients, and spread a 3-inch layer of organic mulch to protect the soil and provide ongoing nutrient support.

What can you grow in the fall?

Think broccoli, cauliflower, kale, radishes, turnips, lettuce, spinach, chard, beets, carrots, and more. The key is to plant them early enough to mature in cooler weather.

Let’s do some simple math.

Check the “days to maturity” on your seed packet or the label on your seedlings from the nursery.

In fall, plants grow slower as days shorten, so add about 14 extra days to that number. For instance, Clementine cauliflower takes 55 days to mature, so aim for 69 days. If you want your cauliflower ready by the first frost (say, Nov. 7), count back 69 days and aim to plant by the last week of August.

(By the way, bright yellow clementine cauliflower’s nutty flavor is beautiful and tasty. Plant purple moon cauliflower — too-gorgeous and delectable.)

Planting cool-weather crops in the heat of summer can be tricky.

• Start seedlings indoors to control the temperature. It’s probably too late to start them from seed now, but I like to start them no later than July 1 so I can transplant vigorous plants that can better tolerate the hot weather.
• Use shade cloths to cool garden beds. I found shade cloth online that blocks 30-50% of light, perfect for protecting seedling beds during a heat wave. It lets in enough light for the plants to grow while keeping them cool and happy.
• Plant in shaded areas and transplant later.
• Water frequently with cool water.

Fall’s cooler weather means fewer pests, but warm days can still attract invaders. When you transplant them into your garden, use a row cover to keep out slugs and butterfly and moth caterpillars from chewing the leaves.

The rule of thumb is to harvest fall veggies before the first hard freeze. However, they can continue growing on sunny fall days with protection from light frost. Use milk jugs, wire fencing with plastic covers, or floating row covers to protect plants during early cold snaps.

Didn’t grow from seed? No problem.

If you didn’t have a chance to start them earlier this month, you can still find a selection of seedlings from garden centers and farmers markets. That’s what I did last year — I found mine at our local farm store. Plan ahead and buy fall seeds in spring next year for a better selection. This year, I planned ahead and have a variety of seedlings growing indoors.

There are some excellent planting guides to help you choose what to grow and when to plant and harvest. A great resource is a fall and winter growing guide from Territorial Seeds that you might find helpful. Just think — you can offer delicious vegetables from your garden at Thanksgiving dinner!

Did you know the WSU Master Gardeners offer the Evergreen Thumb Podcast? Listen to various gardening topics suited for our specific climate in the car or while you’re puttering around the house or garden.