By Brent McGhie, Butte County Master Gardener, March 18, 2016.
Late March is the time to start thinking about thinning the fruit on peach, nectarine, plum, pluot, apricot, apple, and pear trees.
To produce fruit that is large and healthy, fruit trees need plenty of leaves to feed the developing fruit. Since trees often set far more fruit than their leaves can adequately support, it is generally a good idea to remove a percentage of the developing fruit. Thinning fruit improves the leaf-to-fruit ratio, which results in improved fruit size and quality. Thinning also reduces the overall weight of fruit, thus decreasing the possibility of overburdened limbs splitting or breaking. In addition, over cropping can trigger alternate bearing, with significantly less fruit production the following year. Thinning can also limit the spread of diseases such as brown rot of fruits that are touching one another.
Fruit should be thinned when it is about three-quarters of an inch in diameter. Thinning is usually done from early April to mid-May, depending on whether the fruit is an early-ripening or late-ripening variety. Fruit should be thinned when it is about three-quarters of an inch in diameter. If fruit is smaller than this, it may be too hard to see, but if thinned when the fruit is larger than this part of the advantage of thinning will be lost. The larger the fruit is when it is thinned, the smaller the ripe fruit will be at harvest. In other words, it is best to thin fruit early -- but not too early. Thinning also provides an opportunity to remove small, misshapen, or damaged fruit, and these should be the first ones eliminated by thinning. Retain the largest fruit whenever possible.
Rather than pulling it from the branch, fruit should be hand thinned either by 1) twisting it off the stem, 2) pinching off the stem between the fingernails of the thumb and index finger, or 3) using clippers. Peaches and nectarines should be thinned to about five to eight inches apart on the branch. Plums and pluots are smaller, so they can be slightly closer together, about four to six inches apart. Apricots are smaller still and can be thinned to about three to five inches apart. Apples and pears produce clusters of flowers and fruit from each bud and should be thinned to one fruit per cluster. However, if the crop is light, two fruit per cluster is acceptable. If the apple or pear crop is heavy, the fruit should be spaced no less than six to eight inches apart. Since the stems of apples and pears are relatively thick and tough, it is best to use clippers to thin them.
Most home fruit growers do not thin enough fruit from their trees. While it may be hard to thin off that potential fruit, if thinning is done properly both the harvester and the trees will reap the benefits.
For more information on fruit thinning, see
"May in the Garden." Butte County Gardening Guide and Three-Year Gardening Journal (2015): 38.
By Barbara Ott, Butte County Master Gardener, March 4, 2016.
Humans have been observant students of nature for millennia. Over time we have selected grasses that produce heavy-headed grains and we've turned tiny bright flowers into large garden show-offs. The development of seeds by hybridization can be done by anyone willing to selectively move pollen by hand from plant to plant within a plant family. Learning how a plant grows, when it reproduces, and if it is an annual or perennial will aid anyone who wants to experiment with propagating seeds to make new plants.
Plants that form a mass (such as day lilies) can be divided, usually in the early spring, by using a sharp shovel to dig into the mass and separate it into parts to form new plants.
Plants that can be propagated via leaf cuttings (like African violets) can be started at any time by taking a leaf, setting it into soilless plant medium (such as perlite) and keeping it moist, but not wet.
Hydrangeas can be propagated in the spring by pruning off five- to six-inch sections of nonflowering shoots that have two to three pairs of leaves (take your cuttings from close to the bottom of the plant, as woodier cuttings generally produce more roots). Remove the leaves directly above a node (a leaf-growing bump on the stem). Clip the remaining leaves in half, to help increase root production. Fill five-inch pots with rooting medium; and press the cuttings into the medium, keeping the leaves above the soil surface. Water and place under plastic or glass to make a humid environment. Old cracked aquariums can serve as “greenhouses” for cuttings. Place the Hydrangea cuttings in bright filtered light. Once roots develop, a new hydrangea is ready.
To propagate salvia from basal stem cuttings (cuttings near the plant's base), clip in early- to mid-spring. Strip leaves from stems and snip off the shoot tip. Make sure you have a node near the bottom of the stem. Place the stem into a small pot filled with a 50/50 measure of sand and perlite, and keep it warm and moist. The resulting plant will bloom that summer. To make a soft stem tip cutting from salvia, make the cutting in early autumn following the procedure described above. Autumn cuttings need to be wintered over in a warm environment, and then planted in the spring.
Keep in mind that warmth from an electric seed pad will help cuttings root and grow readily.
If you want more plants but don't want to purchase them, make some of your own!
By Barbara Ott, Butte County Master Gardener, February 19, 2016.
References to the plant genus Dianthus go back as far as the Greek botanist Theophrastus. He named these plants from the Caryophyllaceae family “divine flower” (dios = divine plus anthos = flower). The Romans brought Dianthus to Europe and England, and from there these plants were eventually brought to the New World. As it moved to new places, this world-travelling plant acquired a variety of names, including sweet William, pinks, gillyflower, cottage pink, carnation and clove pink.
Dianthus can contribute to garden design in many ways. Use dwarf and mat-forming varieties as edging for a border, in containers, in rock gardens, among patio pavers, as ground cover, or along rock walls. Medium-to-tall varieties are effective in flower borders, in gardens for cut flowers, and in front of shrubs. Combine Dianthus with plants that harmonize with its foliage and colors; good companions include coral bells, feverfew, lamb's-ear, larkspur, lavender, hardy geraniums, petunias, poppies, sage, and floribunda and shrub roses.
Dianthus is a culinary flower. Crystallized petals are used for decorating cakes, while fresh petals can be used in salads, pies, and sandwiches. It is important when using dianthus for culinary purposes to remove the petal base, which is quite bitter.
These varieties of Dianthus do well in our area:
- Sweet William is biennial. It is covered with spicy-smelling, bi-colored flowers in late spring and grows 12 to 18 inches tall. This flower seeds freely. If you don't want seed set, conscientiously deadhead after bloom. But if you love a spontaneous surprise in the garden, sweet William's freely-seeding behavior can provide new plants year after year.
- Cheddar and cottage pinks are perennial forms of Dianthus. Their foliage is blue-gray or green. Some varieties grow as low as 2 inches, others as tall as 16 inches. The low-growing varieties work well in rock gardens.
- Dianthus (D. chinensis), while technically a biennial, is used as an annual. It is low- growing with green foliage, and flowers for up to 8 weeks in the spring.
- Among the taller Dianthus, D. caryophyllus is the best known. This species includes the florists' carnation as well as border carnations.
All forms of Dianthus were characterized by short blooming seasons until 1971, when a breeder began to grow varieties that didn't set seed. These varieties typically bloom from May to October.
Whether you grow old fashioned pinks, sweet William, or hybrid Dianthus, know you are planting a water-wise plant that has graced gardens around the world for millennia.
By Brent McGhie, Butte County Master Gardener, February 5, 2016.
Not all of these plants are technically bulbs. Both gardeners and plant companies alike tend to group true bulbs along with corms, rhizomes and tubers under the general heading of “bulbs.” A true bulb consists of layers of fleshy leaves, like an onion. Amaryllis, Chalochortus and lilies are true bulbs.
Corms are shaped like bulbs, but are solid (not layered) inside. Crocosmia, gladiolus and Liatris grow from corms.
A tuber is actually a fleshy underground stem and its “eyes” are buds from which new plants can develop. A potato is the most familiar example of a tuber. Tuberous begonias grow from tubers (other begonias form rhizomes) and dahlias develop from tuber-like roots. Rhizomes are actually underground stems. Cannas, callas and tuberose are summer-blooming plants that produce rhizomes.
Bulbs need well-drained soil and will often rot if planted in soggy soil. When planting a bulb, loosen the soil past root depth and then amend it with compost or other organic material before placing the bulb in its hole. Commercial fertilizers formulated specifically for bulbs are also available and are normally worked into the soil beneath the bulb at planting time. There may be some individual variation, but generally most true bulbs, corms and tubers should be planted about three times as deep as they are wide. Rhizomes should be planted just under the soil surface, while tuberous roots (e.g. dahlias) should be covered by three or four inches of soil.
Like most plants, bulbs benefit from regular watering during the growing season. Once they have flowered, the spent blooms can be deadheaded, but don't cut back any green leaves. The plants need these leaves to photosynthesize and to replenish the food lost by the bulb during growth and flowering. Once the leaves have browned off, they can be removed. Over time, most bulbs will multiply and become naturalized. To avoid overcrowding and encourage plentiful blooms, it is a good idea to divide the clumps of bulbs every two or three years.
It's too late this year to plant other summer-blooming bulbs, but if you want to plan for next year, Allium, Anemone and Watsonia can be planted this fall. There are also several native bulbs that should be planted in the fall. Species of Brodiaea, Sisyrinchium (blue-eyed grass) and Triteleia (Ithuriel's spear) all bloom from late spring to early summer. Soaproot (Chlorogalum) blooms appear from May to August. If you do buy native bulbs, be certain you buy from reputable dealers who propagate their bulbs rather than collecting them from the wild. This will help ensure these beautiful wildflowers will be available for others to see for generations to come.
By Michael-Anne Foley, Butte County Master Gardener, January 22 2016.
When is soil more than just dirt? When you want to grow healthy plants in your yard and garden, the soil is as important a factor as are water and sunlight. You can improve your soil's ability to support thriving plants of all kinds by protecting it from compaction, amending it with nutrients, and adding mulch as a top dressing. An ideal soil includes various proportions of clay, sand, humus, water and air. You can smell a good soil!
Why is Compacted Soil a Problem?
Compacted soil has less air and is less porous than well-aerated, friable soil. This means it is harder for roots in compacted soil to grow and harder for those roots to get air. Restricted roots are often unable to take up sufficient water or nutrients from the soil. These conditions inhibit plant growth, particularly during drought if soils are dry.
Compacted soil layers can either hold water in (by creating poor drainage), or keep water out (by preventing inadequate water infiltration and creating conditions that are too dry for plant growth and development).
A large number of organisms make up the “soil food web.” They range in size from tiny one-celled bacteria, algae, fungi, and protozoa, to nematodes, earthworms, insects and plants. These organisms are beneficial to plant health but also have difficulty living in compacted soil.
How to Prevent Soil Compaction
- Keep foot traffic limited to a few areas in the garden by using consistent pathways.
- Avoid walking on wet soil and in areas where you have recently loosened the soil.
- Working compost into soil can help alleviate soil compaction by improving soil structure, aeration, and water-holding capacity.
Amending the Soil
Soil amendments improve the physical properties of soils. They increase the water and nutrient-holding capacity of soil and improve aeration and water infiltration. Soil amendments are more than simply fertilizers. Fertilizers (especially synthetic chemicals) add nutrients to the soil for immediate use by plants, but little is retained in the soil. Soil amendments such as compost, humus, worm castings, and aged or composted animal manures improve the soil by making its texture and drainage more conducive to plant health. Soil amendments add nutrients to the microbes in soils, and the microbes then make those nutrients available to plants. The soils that help our foods and landscape plants grow are not sterile but are filled with microbes that are unseen by human eyes. These microbes make our soils healthy and productive.
Amendments are best chosen for the needs of the soil based on how the plants are performing. Landscape plants, annual flowers, and vegetables all have different needs. Commercial producers of amendments tailor blends to generalized garden uses. Some companies offer specific combinations of amendments for specific needs. Worm castings and homemade compost have been found to be among the best amendments because their ingredients are completely broken down and plants cannot be burned by concentrated synthetics.
Two useful websites to consult when determining appropriate amendments for your own yard are the “Analyses of Soil Amendments” at Analyses of Selected Soil Amendmentsand “Amendments for Landscape Soils” at Amendments for Landscape Soils
Using Mulch in the Garden
Mulch performs a number of important tasks in the landscape, and is particularly useful for the following purposes:
- Smothering weeds
- Retaining soil moisture
- Moderating soil temperature
- Feeding the soil by adding organic material as the mulch breaks down
- Alleviating soil compaction by absorbing pressure due to foot traffic
Types of Mulch
Mulch can be organic or inorganic. Each type has its uses in the landscape.
- Yard waste: grass clippings, leaves and small twigs can be used as mulch in moderation and may be best for use behind bushes or borders. Mulching with yard waste functions better when it is composted first. Because yard waste tends to look unsightly, a uniform mulch is often more attractive.
- Straw keeps weeds down and is good for vegetable gardens. It has a short life span.
- Pine bark and needles are good for weed control. Barks last longer, while needles allow water through.
- Wood chips: bark and wood pieces are attractive, provide good weed control and save water.
Inorganic mulch
- Landscape cloth of a woven material provides good weed control, allows air and water to pass through and, if used with organic mulch, can save time and labor for years to come.
- Black plastic can work well for annual plants like strawberries that can be planted through holes in the plastic mulch. Landscape plants, however, will not get enough air, water or nutrients.
- Rocks and gravel are relatively permanent but can be expensive. Decomposed granite tends to stay in place and look tidy.
- Spread a two-to-four-inch layer of organic biodegradable mulch over tree roots, shrubs and plant beds. Keep mulch two inches away from the woody trunks of trees and shrubs.
- Replenish annually or as needed to keep a two-to-four-inch layer. This depth is ideal for weed suppression and water conservation.
As you plan your 2016 garden, keep in mind the importance of keeping the soil aerated by preventing compaction, amending the soil, and mulching to conserve water and fight weeds.
