- Author: Help Desk Team
At the end of the gardening season, there is an instinct to uproot spent plants and clear the soil for a fresh start, whether it be for a cover crop, a winter vegetable crop, or next year's summer crops. There are some really great reasons why pulling out roots after cutting back the plants' top growth is not necessary and can even be detrimental.
The roots that remain after removing your vegetable plants in the fall or cover crop plants in the spring are slowly decomposed underground by worms, bacteria, fungi, and other beneficial soil organisms. These organisms perform a vital role in the soil. As leftover roots decompose, they release organic matter and nutrients into the soil.
Decomposing roots enhance soil structure, making it more porous and helping with aeration. They contribute to the soil's water retention capacity. Organic matter released during decomposition acts like a sponge, holding onto moisture. This creates a good environment for beneficial soil organisms like fungi, bacteria, and invertebrates.
The network of roots left in the soil helps prevent erosion. The root systems act as anchors, binding the soil together and reducing the risk of it being washed away during heavy rain. This is especially important on slopes to maintain the integrity of the topsoil.
And finally, leaving the roots saves gardeners time and energy!
What if you want to plant something in that bed with the roots still there? Seeds or seedlings can easily be planted through and around the remaining roots. Those decomposing roots will help feed the new plants.
Is there ever a reason to remove roots? Yes. Occasionally inspecting the roots of plants you're removing is a good idea to check for root knot nematodes or other root problems. These microscopic roundworms attack a wide variety of plants. They cause swellings (galls) on roots that interfere with the nutrient and water transport system. If you noticed some of your plants didn't look as healthy as they should, it would be valuable to take a look at the roots. For more information about root knot nematodes, see this link: https://ipm.ucanr.edu/PMG/PESTNOTES/pn7489.html
Help Desk of UC Master Gardener Program of Contra Costa County (SEH)
- Author: Help Desk Team
Lettuce may not be a garden crop that causes you to perk up and say, “Tell me more.” You may be thinking, “Boring, I'll pass.” Or you may be the gardener who says, “I never could get that crop to grow.” Whatever your current thinking about lettuce, I hope to get you excited about this humble crop. There are not many garden vegetables with more diversity than lettuce, with more than 100 varieties in a wide range of colors, textures, and shapes.
If you need more encouragement, lettuce is a great hydrator, being 95% water. Lettuce is a powerhouse when it comes to vitamins and minerals. Vitamins A and C play a strong role in supporting the immune system, eyesight, and reduce inflammation. Iron, folic acid, calcium and potassium also add to the health benefits of lettuce.
Lettuce (Lactuca sativa) has been cultivated for thousands of years. The name is derived from the milky liquid produced when a leaf is broken from the stem.
Cool Season vs. Warm Season
We tend to think of lettuce as a light summer food, but lettuce is a cool weather crop. The optimum growing conditions for lettuce occur in fall and early spring. Many cool season lettuce varieties have good tolerance for cold temperatures and do well in low-light conditions.
Summer lettuce is in high demand as a crop, causing breeders to develop lettuce varieties for summer growing conditions with good success. These lettuce varieties are bred specifically to be heat tolerant and are slow to bolt and less bitter as they mature.
Seed Germination & Transplants
Lettuce seeds will germinate in 3–10 days depending on conditions.
Seeds can germinate in soils as low as 40°F but germination will be slow. The optimum temperature for seed germination is 55°–65°F. Above 70°F lettuce seeds germinate poorly, resulting in undersized, misshapen, elongated heads. At higher temperatures lettuce seeds may completely fail to germinate.
Fall lettuce seeds need to be in the ground in late September so they can reach 75% maturity going into the low-light days and cool nights of our winter months.
Spring lettuce seeds should be started indoors in early February. This will give you a jump on planting out in the spring after all danger of frost is past. Continue to sow seeds at 2-week intervals for continuous production.
Lettuce seeds are very small and should be planted with a very light covering of soil (¼ inch). Be generous when sowing your seeds, as some will not germinate, and others may be lost to birds. As they mature, the thinnings can be added to salad or used in sandwiches. The final spacing for lettuce plants should be 9–12 inches.
Many gardeners start with lettuce transplants from a local nursery, followed by seed sowing at 2-week intervals. This gets you off to a quick start and keeps you in a continuous supply of lettuce. To keep your lettuce crop growing through the summer switch to a variety listed as heat tolerant or slow-to-bolt.
Soil Preparation
Lettuce does best in loose, well-drained soil with a generous addition of compost added before planting. A source of organic nitrogen can also be added to the soil before planting. Alfalfa meal, cottonseed meal, and fish or kelp meal are all good sources for slow, consistent nitrogen release.
Watering & Fertilizing
Keep the top 1–3 inches of the soil consistently moist as lettuce roots are shallow and dry out easily. You will want to provide adequate nitrogen for this fast-growing crop. Organic fertilizer is slower to become available. If you are using transplants, give them an application of liquid fertilizer 2 weeks after transplanting.
Frost Protection & Shade Cloth
Winter grown lettuce, though it can tolerate cool temperatures, will need protection from frost, while summer grown lettuce must have some shade protection.
Harvesting
Many lettuces can be harvested as baby greens. Some of the looseleaf varieties can be harvested in any stage of development by cutting the larger outside leaves and leaving the smaller inner leaves to mature. Mature lettuce does not get better, it gets bitter, so don't wait to harvest. To keep lettuce at peak freshness, harvest early in the morning. Wash the leaves thoroughly in cold water, then remove as much excess moisture as you can—a salad spinner is a great tool for this job. Store lettuce in the refrigerator in a plastic container with a lid with several damp paper towels added to create a humid environment. Garden fresh lettuce, stored in this manner, will last 7–14 days.
Disease & Pests
The most common diseases of lettuce are Botrytis rot, lettuce mosaic virus, and mildew. Keeping lettuce leaves dry is the best way to avoid disease from getting a foothold. Good air circulation and drip irrigation are two helpful practices.
Lettuce may fall prey to occasional pests including cutworms, leafminers, caterpillars, aphids, whitefly, snails/slugs and earwigs. Access the UC IPM website for information on controlling specific disease, insects, and vertebrate pests such as birds and deer.
https://ipm.ucanr.edu/home-and-landscape/lettuce/index.html
Lettuce Types
Butterhead / Boston / Bibb: These lettuce varieties form a round, loose head. They range from delicate and buttery to bright and crisp. Leaves tend to be large, making them an excellent choice for wraps and sandwiches. *Days to maturity 45–55. These varieties can be harvested anytime during development.
Looseleaf: This lettuce grows from a central stalk but does not form a head. These varieties are easy to grow and perform well in shaded areas or in low light. They are tolerant of warm temperatures and are slow to bolt which make them a good choice for multi-season growing. *Days to maturity 45-55. These varieties can be harvested anytime during development.
Crisphead / Summercrisp / Batavian: These lettuce varieties are known for their crisp snap and sweet flavor. They form a round, compact head. Often the outer leaves are darker with tender light leaves in the interior. Crisphead is a true cool weather variety which will stand up to very cool temperatures but beware, it is quick to bolt when temperatures rise and it's a favorite of snails and slugs. This would be a good choice for starting indoors in January for transplanting in February after all danger of frost is past. *You will need to plan ahead as some of these varieties take 70-100 days to reach full maturity.
Cos / Romaine: This lettuce is very upright, forming a column. They can be tightly closed, semi-closed, or open heads. This lettuce has a crisp, creamy white heart with the outer leaves remaining sturdy and dark. It is unforgiving of poor growing conditions and is not well adapted to warm weather. There are interesting varieties in the seed catalogs with some beautiful deep burgundy varieties in the offering. *You will need to plan ahead as some of these varieties take 75-85 days to reach full maturity.
I hope I have piqued your interest in experimenting with both winter and summer lettuce in your garden. The varieties and variations are truly exciting, many of which you will never see in your supermarket or even at farmers markets. Whether you select your varieties by color, shape, texture, or even their fun names, I hope you have decided to give lettuce a place in your garden. May it be a delightful and successful experience!
Help Desk of UC Master Gardener Program of Contra Costa County (BHD)
- Author: Help Desk Team
This year was particularly bad for peach leaf curl and other fungal infections in fruit trees because of the wonderful rain we had last winter and spring. It looks like we might have another wet winter, so we are rerunning this post to remind you to think about a spray program for your trees.
Now that the leaves have fallen, or mostly fallen, from your backyard fruit trees, are you wondering whether you should apply dormant sprays?
“Dormant sprays” or “delayed dormant sprays” are terms used for the application of pesticides when the tree is dormant or just coming into bud swell. The pesticide could be a fungicide used to help manage fungal disease or a horticultural oil or oil in combination with insecticides to kill insects.
Don't assume that you need dormant spray. Before reaching for the spray, first determine whether your trees have previously had a disease or serious insect pest problem that can be managed with dormant sprays. Have you already tried all non-chemical recommendations for lessening the problem? Finally, evaluate the amount of damage from the disease or insect pest you experienced in the prior growing season to decide whether a pesticide is really needed.
Fruit tree diseases that can be managed by applying a fungicide dormant spray include peach leaf curl, brown rot, and shot hole disease.
Peach Leaf Curl
Peach leaf curl affects only peach and nectarine trees. It shows up in spring after the tree has leafed out. Leaves are thickened, curled, and colored red or yellow instead of normal green.
If your tree has had significant peach leaf curl in prior years, dormant spraying with a fixed copper spray just after all the leaves have fallen from the tree (usually December to January in our County) may prevent or reduce the severity of the disease. For information on managing peach leaf curl, see https://ipm.ucanr.edu/PMG/PESTNOTES/pn7426.html/
Brown Rot
Brown rot (Monilinia) is a fungal disease that can affect peaches, plum, cherries, apricots, and nectarines. In the spring blossoms on infected trees shrivel and die, often clinging to the twigs. Leaves at the base of infected twigs may also turn brown and die. Fungal spores attach themselves to developing fruit and show up as brown or tan spots on the surface of the fruit.
If your trees had significant fruit loss from brown rot in the prior growing season, a dormant spray of a copper-based fungicide may help. Apply it at the pink bud stage while flower buds are still tightly curled and pink in color. For more information on brown rot, see http://ipm.ucanr.edu/PMG/GARDEN/FRUIT/DISEASE/aprbrownrot.html.
Shot Hole
Shot hole (Coryneum blight) can affect plums, nectarines, peaches, cherries, and especially apricots. It shows up as small reddish holes on leaf surfaces. Often the holes turn brown and drop out. Fruits may also be infected. Where disease has been severe and cultural steps haven't helped, a fungicide spray following complete leaf drop may be needed. See http://ipm.ucanr.edu/PMG/GARDEN/FRUIT/DISEASE/shothole.html.
Brown Soft Scale
Insects that can be managed with dormant sprays of horticultural oils or oils mixed with insecticides include scale, aphids, and spider mites. Don't spray unless you have confirmed that the insects are present in damaging numbers and cannot be controlled by other means. Keep in mind that spraying may also kill beneficial insects which are the first line of defense against insect pests. More information on controlling these insect pests can be found at these UC websites: http://ipm.ucanr.edu/QT/scalescard.html, http://ipm.ucanr.edu/QT/aphidscard.html and http://ipm.ucanr.edu/QT/spidermitescard.html.
Caution: Before spraying, read and carefully follow the label instructions on the pesticides you use, including wearing recommended protective gear.
Help Desk of UC Master Gardener Program of Contra Costa County (TKL)
- Author: Help Desk Team
Note: We are running this previously published article because it's important to be ready to protect sensitive plants. Don't get taken by surprise!
It's time to get ready for cold winter temperatures and to start preparing protection for citrus trees and other frost-sensitive plants. Depending on where you live in Contra Costa County, your first frost date may be as early as Halloween. However, November 15 is often thought of as a first frost date in much of our County, with slightly earlier in the eastern portion and later in the more temperate West County areas. Because significant climate variation can occur, it's good to start thinking of frost protection early, before you need it.
Frost can start to occur when the temperature gets below 36°F and is sure to happen at 32°F. When temperatures drop below 32°F, it becomes a freeze, and if it drops below 28°F, it's a hard freeze.
Protecting plants when temperatures drop in the Bay Area can be done using three simple elements:
Water: It may seem counter intuitive, but water can provide protection from freezing temperatures. When dry soil freezes, moisture is pulled from the roots, causing damage. If the soil is moist, it can freeze without harming roots. Wet soil also holds more heat than dry soil. When the forecast calls for 32°F or below at night, water the ground around your plants lightly in the late afternoon or early evening. The exceptions to watering plants before frosty temperatures are succulents. They need to be kept dry when a freeze is expected if you can't move them into a warmer spot.
Frost Covers: Protect tender plants and trees with frost covers either purchased or homemade. Sheets, blankets, tarps, or burlap can be used, but these need to be propped up above the leaves and removed in the morning. These materials can become wet with dew and damage sensitive leaves. Commercial frost cloth comes in several weights and can provide up to 4°F protection (find it at your local nursery or home and garden store). It can float over the top of the plants and can be left on for several days since light can pass through it. For very sensitive plants, make sure the cover goes all the way to the ground. If very cold temperatures are forecast, also wrap the trunk of a young citrus tree with cardboard to protect the bud union and above.
Covering or tenting should be done in the late afternoon or early evening when freezing temperatures are predicted, then removed in the morning after frost has thawed to allow for healthy air circulation and to allow the soil to warm in the sun.
Heat: Moving potted plants indoors, into a greenhouse, or even grouping them together under a tree or house eaves to conserve heat will give enough protection for many plants. A light bulb (100-watt designed for outdoor use) or Christmas lights (old-fashioned incandescent type lights—LED lights do not emit enough heat to help) under a frost cover can add additional heat. Make sure you use extension cords and lights rated for outdoor use.
If plants have suffered damage from frost, wait to prune until spring. Frost-damaged areas on plants can add protection to parts below if there is another freeze. You also don't want to stimulate the plant to put out new tender growth that would surely be damaged in another frost.
Following is a link to a UC publication titled Frost Protection for Citrus and Other Subtropicals: https://anrcatalog.ucanr.edu/pdf/8100.pdf
Help Desk of University of California Master Gardener Program of Contra Costa County (SEH)
- Author: Help Desk Team
Halloween creeping up on you? Well, the UC Master Gardeners have got some boo for you!
Mother nature seems to enjoy providing us with ‘deviant' forms of plants that are strangely shaped and, as a result, we field lots of questions from the public about the peculiar growth of plants in their gardens (especially fruits and vegetables). These questions often arise to make sure that these oddities are safe to eat. Some plant mutations do look a bit alien and maybe even a little possessed, so it's a good idea to be sure they're safe! The good news is that while scary, many of these deviant forms are often perfectly okay to consume (after snapping a photo or two for posterity, of course!).
Two types of abnormal growth that are commonly seen in plants are called fasciation and monstrosity. Fasciation, which can be seen in a variety of plants, including succulents, occurs when normal stems turn into a wedge, fan, or crest. This can lead to plants that are very unlike their parent with smaller leaves, more ribs, altered branching and even suppressed flowers.
Monstrous growth is even more difficult for the plant to deal with. In these cases, it's as though the plant can't decide where to grow from and creates growing points all over the place. Monstrous growth produces all sorts of strange forms.
Another mutation is variegation. In plants, variegation means the appearance of different colored zones on leaves, stems, fruit or flowers. Variegations can be uniform (sometimes called pattern-gene or natural) – this is where the variegations occur in the same way across an entire plant. Variegations can also be random (known as ‘chimeral'). Virus infections can also cause the natural variegation of plants.
As a general rule, mutant forms are weaker growers than their normal forms. They need greater protection from the full sun and they are subject to the same insect pests as other plants though they tend to have more difficulty dealing with them.
Mutations tend to be random and are the result of a change within the cells of the plant, but some mutations can be triggered by environmental conditions such as cold weather, temperature fluctuations, or insect damage. Inadequate pollination may cause sections of a fruit or vegetable not to develop seeds, cease to grow, and impact the shape of the fruit and vegetables. Luckily for us, weirdly shaped vegetables and fruits have the same nutritional value as the normies and are just as tasty.
We've all seen oddly shaped fruits and vegetables such as carrots with legs, crazy-looking strawberries, and eggplants with noses, as well as many other odd shapes that are perfectly normal in some fruits. If you haven't seen any of these monsters, take a look at the photos below!
Wait until this Buddha's Hand Citron gets larger and turns bright yellow! Terrifying!
This is ‘normal' behavior for this Tomato, Phil's One! What in the world?
This odd behavior occurs in strawberries when the seeds try to germinate before they detach from the plant. This may have been caused by environmental stressors such as cold temperatures. The strawberries are safe to eat!
The deformity of this tomato mainly results from abiotic disorders. Abiotic disorders are plant problems caused by too much or too little water, nutritional deficiencies, too much sun and sometimes just common growth in some varieties of indeterminate tomatoes!
What in the world is wrong with this eggplant? A common, yet hard to explain behavior!
This zucchini was found at Our Garden in Walnut Creek in 2021. We believe that this is called everted ovaries and may have been caused by lack of full pollination, a virus, or even spontaneous genetic mutation!
There are so many weird and wonderful plants you can grow in your own garden such as: Romanesco Broccoli, Black Carrots, Dragonfruit, Bitter Melons, Black Tomatoes, Tomato Phil's One, Buddha's Hand Citron, and Jerusalem Artichokes. Check out your local nurseries or seed providers for many monstrous ideas!
Have no fear… Many of the plants we covet in our gardens are actually created by mutations! Thank you, Mother Nature!
Happy Halloween!
Help Desk of the UC Master Gardeners of Contra Costa County (SLH)