- Author: Elinor Teague
Many varieties of citrus and other fruit trees have set a bumper crop of small fruit this season. Alternate bearing or the setting of fewer fruit every other year or two is normal for fruiting trees, but this year's bounty of mini fruit is unusual. The cause could be last season's long, cool, wet spring weather that delayed blossom set and pollination. Or it could be that the immature heavy crop of fruit should have been thinned early. The fruit is juicy and sweet. Just remember that the best way to store citrus fruit is to leave it on the tree until it falls off.
Rose leaves are still bright green and firmly attached to most bushes. Roses will set flowers all winter long if temperatures don't drop to freezing levels. In the Central Valley with its mild, short winters, rose lovers usually strip browning leaves from their bushes in mid-November to force dormancy by using water from a hose to blast off the dead and dying leaves. But you might need to hand strip green leaves from roses this winter. Do it after you've pruned to minimize the work.
Weed seeds germinate quickly when the soil temperature warms above 50 degrees. That often happens during winter warm spells like those we had during December. As you are using a wiggle hoe to cut down tiny weeds, you'll notice that it's much easier to till of the soil in areas that have been kept covered with a three- to four-inch layer of mulch. Those of us who have begun spreading the fall leaves into planting beds instead of raking them up are seeing that the leaf mulch does reduce weed germination, but because we haven't had much rain yet this winter, the dry fall leaves have barely begun to decompose. Rake or blow the leaves to turn them and encourage faster decomposition.
- Author: Elinor Teague
Last season's torrential winter rains provided a much-needed relief from 20 years of drought. However, Central Valley home gardeners deal with the effects of drought every summer because, even with regular irrigation, extremely high temperatures during our long, rainless summers create drought stress conditions.
Large mature shade-producing landscape trees and bushes have been weakened by years of drought. Summer drought speeds up the normal fall process of slowing vegetative growth and also leads to smaller leaves and early leaf drop on deciduous plants. Leaves make food for trees. Trees and bushes with fewer, smaller leaves in fall have fewer stored resources and less food for next year's growth. Small, fine roots die and plants are unable to draw up and store enough water and nutrients to overwinter well and to quickly regain their vigor in spring.
Check soil moisture levels now in several places underneath large tree and bush canopies, especially those that have not received at least monthly deep irrigation during the summer months. The top few inches of soil near trees and bushes in lawn areas may be moist from sprinkler water. Sprinkler water generally only penetrates to a depth of four inches, but try to check moisture levels at least 12 inches deep using a shovel or trowel.
Deep irrigate large, mature landscape trees and bushes in early fall to a depth of 18 inches before dormancy to help them better tolerate cold or below freezing temperatures. Continue to provide monthly slow deep irrigation throughout the winter months unless rainfall from atmospheric rivers provides sufficient water to soak the soil.
Wet soil around the roots provides better insulation against cold temperatures than dry soil. During the next few weeks closely examine your and your neighbors' large trees and bushes for branch dieback to prevent damage from falling dead branches during winter storms. Winter pruning of deciduous trees and bushes should wait until after leaf fall, but dead wood can be removed at any time.
If dead branches are large or higher than 15 feet it's best to hire a certified arborist to do the work. Many large landscape trees were blown over during last year's violent windstorms. Root systems of surviving trees may have been compromised or broken from the soil from high winds. Changes in the angle of the tree trunk as it begins to tip may not be obvious.
Check the soil under canopies for evidence of root uprise with special attention to the northwest and western sides; our winter storm winds generally come from the northwest or western direction. If you see signs of tree tipping consult a certified arborist who can determine whether the tree is unsafe and should be removed before the winter storms.
Newly planted trees and large bushes should be properly staked to help them stand up to strong winds. Use strong poles and cushioned ties on the trunk and position the poles or stakes at the edge of the rootball on the northwest or west side. Most trees and bushes have a heavier side with more or bigger branches. Check that the heaviest side of the tree or bush is planted to back up to the northwest or west. Replant if necessary to correctly balance the new tree against the force of winter winds.
- Author: Elinor Teague
The look of neighborhood yards has changed radically these last years. Landscape designs that feature highly-manicured, constantly trimmed, raked, and groomed lawns and planting beds are disappearing, by necessity. Traditional formal plantings (visualize rose beds inside boxwood hedges) are being replaced by drought and heat-tolerant California native and pollinator-friendly plants and trees better suited to our Central Valley climate and better able to survive extreme heat spikes as well as the high winds and heavy rainfall that come with atmospheric river 'bombs.'
Mulches are always recommended as covers for bare soil in the landscape for water conservation, soil temperature moderation and weed prevention, but the thinking on mulches is changing. Wood chip, straw and cedar shaving mulches are expensive and they release minor amounts of nutrients into the soil as they decompose. Leaf mulches from your own well-established trees or your neighbors' trees contain 50 to 80 percent of the nutrients the tree extracts from the air in a season.
The rapid composting method is one easy way to create leaf compost, but leaves that have not yet been composted can also be used as mulches. Leaves that fall from some deciduous large landscape trees (Japanese maples, liquid ambars, Chinese pistache) can actually be left intact to use as mulch underneath the trees. Lighter-weight leaves will break down fairly quickly during the fall and winter months.
Rake or spread the leaves to maintain an even depth of about two inches. Thicker layers of whole leaves can block water and oxygen as the leaves break down and become compacted. You can add more leaves as the leaf layer breaks down.
Leaves from evergreen broadleaf trees like Southern magnolia and California bay take longer to break down and should be shredded before being used as mulches. A three- to six-inch layer of shredded leaves is optimum underneath the trees' canopies.
Use a mulching mower to shred the leaves or a shredder. Shredders are now smaller, lighter and less expensive. The one-time cost of a shredder or mulching mower will soon recoup the repeated expense of buying mulches every planting season.
Shredded leaves can be used as a one-inch deep mulch layer on lawns. Spread the leaves thinly so that the grass blades show through. Add a two- to three-inch layer of shredded leaf mulch to cover your planting beds in winter, keeping the mulch a good four inches away from stems and trunks to prevent rot.
By spring the leaf mulch will have turned to nutrient-rich leaf mold that can be dug in as a soil amendment. Uncomposted leaf mulch will be host to many insects, insect eggs and pupae including butterflies, moths, spiders, ants and beetle species. Remember to leave some areas of bare unmulched soil in your garden to provide habitats for ground-nesting bees.
Leaves from trees that have had fungal problems (anthracnose, fireblight) or pest insect infestations (whiteflies, scale, aphids) should not be used as mulch. The wintertime decomposition process will not create enough heat to destroy fungal spores or pest insects and their eggs.
Sources:
www.familyhandyman.com/article/leaf-mulch
https://xerces.org/blog/midwinter-tasks-for-pollinator-gardening
- Author: Elinor Teague
Preparations for severe weather and damage control in home gardens and orchards have become a major focus for Master Gardeners during the last 10 years. California Master Gardeners are helping home gardeners deal with drought, with atmospheric river ‘bombs' that bring high winds, heavy rains and flooding, with heat spikes and with wildfire smoke and ash. This year we also experienced extended cold spells with night time temperatures near freezing until April.
Here's a brief review of the major problems home gardeners are facing and some ideas for mitigation of the results of severe weather.
Drought: Amend the soil in planting beds with large amounts of compost and humus twice a year to increase water retention and retard runoff. Replace lawns with drought-tolerant plants and California natives and install water-conserving irrigation. New irrigation devices come onto the market every year; check them out frequently. Consistently maintain a three- to four-inch layer of organic mulch. Leave the leaves from healthy trees to decompose in beds rather than removing them. This preserves beneficial micro organisms in the soil and encourages the development of beneficial fungi that create hyphae, or long fungal threads, which add structure to the soil.
Atmospheric river ‘bombs': Prepare for heavy rain and flood control in the landscape. Fill in low spots, create slopes and shallow trenches within the landscape to carry water away from structures. Amend compacted soil with compost or humus. Replace concrete areas with pavers, bricks or decomposed granite that will allow water to percolate into the soil below.
High winds: Support smaller trees with two stakes placed just outside the root ball to the west/northwest side of the tree, the direction of the prevailing winter storm winds in the Central San Joaquin Valley. When planting new trees always position the tree so that the heavier side with more branches or bigger branches is to the northwest, to help balance the tree against the wind. Plan on regular pruning to remove broken, dead or diseased branches and to correct weak branch structures.
Heat spikes: Deep irrigate a day or two before a heat spike, or several consecutive days of temperatures above 100 degrees, is predicted to arrive. Plan on hand watering container plants twice a day during long hot spells. Move containers into the shade during hot spells and provide afternoon shade for crop-producing plants with movable shade structures.
Wildfire smoke and ash: Wash off ash and dust from trees and bushes frequently and try to direct the water into planting beds. Cover crop-producing plants temporarily with tarps or row covers to keep pollutants from tainting the fruit or vegetables.
Long cold spells: The longer cold season this year really disrupted the (used-to-be) normal spring flowering schedule and delayed planting time for warm-season vegetables and flowering annuals. Transplants and seedlings were stunted by the cold and did not recover full vigor until mid-summer, so ripening and harvest have also been delayed. Home gardeners who compete to bring in the first tomatoes in summer or serve the last tomatoes for Thanksgiving in November may need to invest in heat-retaining row covers or heat-reflecting mulches and materials.
