Tips for planting fall veggies

Sonoma County Master Gardens talk fall veggies and seed saving.|

Q: I love leafy greens, broccoli, Brussels sprouts, kale and a variety of other vegetables in my fall garden. Any tips for success?

A: A successful garden of delicious, nutritious fall vegetables is all about knowing what you want to plant, when you need to plant it and how you will plant it.

Once you have decided what veggies you want to plant, timing is critical. Typically, in Sonoma County, if you start planting in warm soil in August and September, your vegetables will mature in cool weather before Thanksgiving. Here are the key things to consider:

  • How long it takes your crops to mature
  • The first date of frost in your area (find info about Sonoma County areas at bit.ly/3yNleqz)
  • The last day with 10 hours of sunlight (Nov. 18)

How long it takes crops to mature, or days to maturity (DTM), can be found on seed packets. Or you can look at the Vegetable Planting Summary at bit.ly/3vAfgao. You want to sow or transplant on a date that gives crops enough time to mature before the first frost date or Nov. 18, whichever is earlier. Since fall days are shorter and cooler, add seven to 14 days to the DTM to calculate the best planting window.

You also need to decide whether to start seeds indoors while your summer crops are finishing or to buy seedlings to transplant.

Assess your summer veggies. Are you getting tired of squash? Are your cherry tomatoes really past their prime? You could remove some plants to make room for your larger fall favorites like cauliflower and broccoli.

If you just can’t give up your juicy red tomatoes yet, try “intercropping.” Plant cool-weather veggies like beets, carrots or lettuce next to your tomatoes, where they can enjoy some partial shade. Make room for the new plants by removing the lower branches of mature tomato plants. When it’s time to remove the tomato plant, cut it down at its base and leave the roots in the ground. However, do not leave the roots in the ground if the plant exhibits signs of disease.

If fall weather remains hot, use a lightweight row cover to protect your fall seedlings. It has the added benefit of keeping end-of-summer pests away from your tender greens.

Keep seeds and seedlings well-hydrated but not wet. Once rain arrives, supplemental irrigation is unnecessary. Apply mulch to retain moisture and reduce evaporation. Keep mulch a few inches away from the base of your plants and don’t cover seed beds until seedlings are 4 inches tall. If your garden bed is within 5 feet of your house, be fire-smart by using compost rather than wood chips or rice straw on top of the soil.

You can find more information about cool-weather crops on our UC Sonoma County Master Gardener website. Some useful links are listed below. Enjoy your harvest!

More resources:

Q: My vegetables are thriving this summer. Can I save the seeds?

A: Although no one year is quite the same as another, using seeds from plants that are already doing well and adapting to your garden conditions can ensure future bounty.

Saving seeds is easy, but keep in mind a few key points:

1. Understand how the flowers in your crop get pollinated. Pollination is the process of moving pollen from the male anther of a flower to the female stigma to create fruits and seeds. Self-pollination occurs within the same flower or another flower of the same plant, while cross-pollination occurs when insects, animals or wind transfer the pollen from one plant to another. These natural forms of pollination are collectively referred to as “open pollination.”

2. Save seed from open-pollinated plants, where the two parent plants share the same characteristics. Hybrid seed is not suitable for seed saving because the male and female parents do not share the same traits. This means the new plants may not have the desired characteristics.

3. Capture seed from as many healthy individuals of the same variety as you can and make sure it is free from debris. This increases genetic diversity and can add more vitality to the crop.

4. Find out how long it takes for your plant to produce seed. If your plant is an annual, it produces seed in one season; biennials, such as carrots or beets, produce seed over two seasons with a cold period in between.

The best vegetables for successful seed saving are from annual, self-pollinated crops like lettuce, beans, tomatoes and peas. You also can save seeds from plants that are cross-pollinated, but they may not be “true to type” if other varieties were growing nearby when pollinators were active.

Allow lettuce heads to mature without harvesting the leaves. A stalk will rise up through the center and form flowers. Three weeks after the flowers fade, the seeds are ready. Shake the tops of the flower stalks into a paper bag to release the seeds.

Let bean and pea pods turn brown. Once the pods are dry and you can hear the seeds rattle inside, they are ready to harvest.

Tomato seeds are ready when your fruit is ready. Cut the tomato in half and scrape out the seeds into a jar or glass. Add some water to the seeds and let them sit uncovered for 3 days while mold develops. The mold dissolves the gel sack that surrounds each seed. After three days, good tomato seeds sink to the bottom. Pour off the liquid and any pulp but keep the seeds at the bottom. Rinse these and dry them on a coffee filter or glass plate. Store the completely dry seeds in a sealed glass jar in a cool, dry area.

To learn more about saving, harvesting and storing seed from plants, visit:

Saving vegetable seeds: bit.ly/373B83q

How to save seeds: bit.ly/2Wjrk2Z

Hybrids and standard (open-pollinated) varieties: bit.ly/3BTRLfY

Contributors to this week’s column were Pat Decker, Electra de Peyster and Stephanie Wrightson. Send your gardening questions to scmgpd@gmail.com. The UC Master Gardener Program of Sonoma County (sonomamg.ucanr.edu) provides environmentally sustainable, science-based horticultural information to Sonoma County home gardeners. The Master Gardeners will answer in the newspaper only questions selected for this column. Other questions may be directed to their Information Desk: 707-565-2608 or mgsonoma@ ucanr.edu.

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