By Susanne von Rosenberg, UC Master Gardener of Napa County
It's the middle of October, we haven't had any rain yet, and I'm working on and thinking about my spring vegetable garden. How can that be?
First of all, the middle of October is more or less the latest time that you can get some cool- season vegetable seedlings into the ground. Most of them, such as the brassicas (broccoli, cauliflower, Brussels sprouts and kale), will not mature before the cold weather sets in. However, they will get a head start in becoming established, develop a strong root system and reward you with rapid growth as soon as the days lengthen and warm up in the spring.
You can still get in one more round of some leafy crops such as fast-growing lettuce or Asian greens. Even if they don't get as big as they would if we had more sunlight and warmth, they will still form a harvestable crop by mid- to late November. Make sure that you protect your little darlings from birds and other critters. At this time of year, anything green and juicy is appealing to wildlife.
Another part of planning for my spring vegetable garden is deciding where to put those October vegetable starts. That means deciding which of my summer crops are ready to come out. This is a good time of year to harvest the last of your tomatoes and cut the plants to the ground or remove them. Tomatoes that ripen later are generally not very tasty and also more likely to succumb to diseases.
Similarly, my pole beans are largely exhausted and ready to be removed. I can't take out all of my squash plants yet because a few are still ripening fruit. However, those that have yielded enough or have only very immature fruits are also coming out. By the way, you can treat those very young winter squash like summer squash; they are edible and tasty.
Because I'm a great fan of cucumbers, I usually coax my cucumber plants as far into the fall as I can. You may also have vegetables that you just really don't want to let go of. That's part of the planning process as well. If you're saving seeds for next year, remember to do that before you remove the plants.
Not all of my summer vegetable plants have to come out at the same time because I don't need all that space for planting. The areas that I'll be planting next spring are great candidates for growing cover crops right now. I like to use fava beans, which are easy to plant. You can eat the young leaves (steamed like spinach) and the flowers (fun in salads), and you can leave some of the flowers to develop into fava beans. I usually like to let the plants mature in those areas where I'll put warm-season crops in late April or May.
Another thing I like to do in the fall is to refresh my vegetable beds, if needed. I have hardware cloth (often referred to as gopher wire) underneath all of my vegetable beds. This year, the gophers broke through in one bed and took out my acorn squash and mini pumpkins.
The other aspect of my spring-garden planning is determining what to plant where and when. I figure out when I need to plant various seeds or seedlings so I can harvest a crop around a certain time. Then I plot where I want to put those plants. I always rotate crops. It's important not to grow plants from the same family in the same spot every year. Crop rotation helps control pests and diseases and also helps balance the nutrient demand in the garden.
Once I know where those plants are going and when, I can decide where to put cover crops and which ones I'll leave in place to harvest. Then I check my seed supply. I make sure that I have the ones I want and that they are fresh enough to use. Some seeds, like lettuce seeds, don't last long, so it's best to purchase new seed ever year. I don't know anyone who plants a full packet of lettuce seeds every year, unless they are growing them as baby lettuce. If you know you won't need all those seeds, consider sharing with friends.
Most brassica seeds, as well as summer vegetable seeds such as tomatoes, squash, melons and beans, are viable for two years. When seeds get too old, they don't sprout as well, and even if they sprout the plants they produce won't be as vigorous. By knowing which vegetable seeds I need, I can order early to make sure I get the seeds I want and they arrive on time.
As you can see, even though the warm weather is winding down, there is still a lot going on in the garden.
Food Growing Forum: Last Sunday of the month through October. Register to get Zoom link at: http://ucanr.edu/foodgrowingforum2020
Sunday, October 25, 3 pm to 4 pm, “Planting Onions, Leeks and Other Alliums and What Else to Do Now”
Napa Library Talks: First Thursday of each month. Register to get Zoom link. http://ucanr.edu/wildlifehabitat2020
Got Garden Questions? Contact our Help Desk. The team is working remotely so please submit your questions through our diagnosis form, sending any photos to email@example.com or leave a detailed message at 707- 253-4143. A Master Gardener will get back to you by phone or email.
For more information visit http://napamg.ucanr.edu or find us on Facebook or Instagram, UC Master Gardeners of Napa County.
Many of us think of August as a time to harvest tomatoes. I'd like to suggest that August and September are also the ideal planting time for fall, winter and spring crops.
In our mild-weather valley we can plant cool-weather vegetables as late as October. How lucky are we to be able to harvest fresh vegetables from our garden almost year round? Put in a few ‘Bibb' or ‘Butterhead' lettuce seeds now and 45 days later you will have plants that can make salads all winter long if you harvest a few outer leaves at a time.
Cool-weather vegetable gardens require much less attention than summer gardens. Because our rainy season coincides with our mild winters, soil dries out slowly. Often very little watering needs to be done.
Moist soil buffers the impact of any frost because the soil doesn't get as cold as the air. Although most vegetables will not survive prolonged severe cold, cool-season crops will survive a few days of 25ºF lows and some will even survive down to 15ºF. The University of California keeps historical frost records that suggest that Napa has only a 10 percent chance of frost at the beginning of November. But the likelihood of frost rises to 50 percent in early December. You have plenty of time to plant now and have thriving plants before winter cold sets in.
Be aware that some cold-weather crops won't grow much during the winter. Root crops such as carrots, beets, radishes and parsnips will hold at maturity in the garden until you are ready to eat them. It's almost like having an extra refrigerator. Kale, cabbage and broccoli will grow slowly but do need to have a good start before the cold sets in.
When choosing cole family crop varieties (kale, broccoli, cabbage), note if they are labeled “early” or “short season.” These varieties are less hardy than those labeled as good for overwintering. Early-harvest varieties were bred for areas with winters too severe for vegetables to survive. They need to reach maturity quickly. Hardiness has likely been bred out of those plants.
Besides being able to harvest over a longer time, you will find another advantage to planting overwintering varieties of carrots, beets, spinach and kale. When these vegetables are exposed to frost, they undergo a process sometimes called cold-sweetening. The plant stores glucose and fructose to guard against frost damage. Sugar dissolved in a plant cell makes it less susceptible to freezing in the same way that salting roads reduces ice. So a little frost often makes these crops taste sweeter.
Many gardeners prefer to plant seeds for these crops directly in the ground. However, if you start seeds inside, you can pop the seedlings into ground that you are now using for a warm-weather crop, allowing you to make optimal use of valuable garden space. Local nurseries and garden centers will also have seedlings available.
Don't forget to give your soil some extra TLC. Because you are utilizing the soil year-round, remember to dig in fertilizer and organic matter more than just once a year. Twice would be good.
When deciding where to plant cool-weather vegetables, don't overlook areas of your garden that are too shady in warm weather. The sun traverses a different path in the sky in summer and winter. So new planting areas may be available. Keep in mind that salad greens and leafy vegetables require only four hours of full sun every day.
I plan to add an extra warm glow to my holiday meals by harvesting and serving vegetables from my own garden. Now that you know how easy it is, maybe you will join me.
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