Good cleanup in January starts the year on a healthy note

Happy New Year! Let’s all spend more time digging in the dirt this year. It’s good for our immune systems, for our mental health and good for the planet, too.

Kick off the new year with a clean garden

  • Clean up and dispose (don’t compost) of leaves from deciduous fruit trees: peaches, plums, apples, etc.
  • Prune away dead branches on shrubs and trees.
  • Prune off dead flower stalks on perennials, flowering trees and flowering shrubs. Gardeners call this “deadheading.” Compost the cuttings.
  • Do not prune away cold damaged parts of plants. The damaged parts protect the rest of the plant from upcoming freezes. Cut off those parts at the end of February.
  • Rake walkways, and mulch under and around plants.
  • Turn your cold compost pile, the one in the corner of your backyard. Turn so the top leaves go to the bottom. Use the finished mulch in your garden.
  • Put away tools, empty pots whose plants have died. Save the used potting soil for future potted plants.
  • Empty and coil hoses after each use. Left under pressure, hoses tend to spring leaks.
  • Fix pinholes in hoses with a metal hose repair kit that matches the diameter of the hose (standard garden hoses are ¾ inch, 5⁄8 inch or 1 inch diameter). Cut the hose on either side of the hole and discard the damaged section. Insert the parts from the repair kit, then use a screwdriver to secure them in place.
  • Clean, sharpen and oil pruners, saws, loppers, etc.
  • Clean up and organize your garden shed. Shelves, drawers and wall hooks help keep tools, hose nozzles, sprayers, twine, plant markers, etc. organized and easy to find. Fishing tackle boxes are great for organizing and storing irrigation parts.
  • Store bagged organic fertilizer in a container with a tight lid to keep out hungry critters.

Water management

  • December didn’t bring much rain, so check your soil’s moisture. If it is really dry, run the irrigation.
  • Don’t overwater. With the cool weather and the sun so low in the sky, gardens need water only on occasion, even if there is no rain. Once a week, once every two weeks, once a month is fine for all except lawns and vegetables.
  • Deep and infrequent, that’s our watering mantra. Water for a long time but not often.
  • Add a dry stream bed, swale or just some depressions to your garden. These are all strategies for capturing and banking rainwater in your garden’s soil.
  • If your laundry room backs to an outside wall, install a simple “laundry-to-landscape” grey water system. Direct the wash water to fruit trees and ornamental plants. Watch Episode 105 of “A Growing Passion,” titled “Cycle and Recycle.”
  • Check your irrigation system for leaks, kinks, etc.
  • Open the ends of drip lines and run the system a few minutes to flush out any grit or debris.
  • Run overhead spray to see that heads are aimed correctly, heads are working properly, etc.

Plant new deciduous fruit trees, vines and shrubs

Shop for bare-root fruit trees, vines and shrubs this month for the best selection and best prices. “Bare-roots” are 1- to 2-year-old plants dug up and their roots washed clean of soil. They look like scraggly sticks with a wad of roots at the base, but don’t worry, they will grow into vigorous, producing plants soon enough.

Some bare-roots — stone fruits, apples and pears — are grafted, which means they are two plants fused into one:

  • The fruiting wood (also called the “scion”) is the top part of the tree. It grows leaves, flowers and fruits.
  • The rootstock is the bottom part of the tree and grows roots.

The best grafted fruit trees for your garden combine the best scion with the best rootstock. You’ll find different options for each:

Choose the fruiting wood based on:

  • The fruits you most like to eat.
  • How many chill hours your garden gets.
  • The time of summer you want the fruit to ripen — early, midseason, late.

Choose rootstock based on:

  • Your garden’s soil (clay, sand, or in between).
  • Pathogens present in the soil — harmful bacteria, fungi, etc.
  • The size of tree you prefer: full size, semi-dwarf or dwarf.
  • Your garden’s chill hours.

For stone fruits, apples and pears, it’s all about winter chill. Chill is basically an accumulation of overnight hours between 32 and 45 degrees from late fall through early spring. Different fruit varieties need different amounts of chill, so it’s important to match the fruit trees to the chill in your garden. Without that critical rest period, the trees won’t produce fruits.

With our multitude of microclimates, chill hours vary from garden to neighborhood to community, but in general:

  • Inland gardens tend to get 100 to 500 chill hours.
  • Gardens just inland of the coast and desert gardens get 100 to 400 chill hours.
  • Right along the coast, gardens get 100 to 300 chill hours.
  • Mountain gardens, like in Julian, can get up to 1,000 chill hours.

See how bare-root plants are bred, grafted, grown, harvested, processed and shipped in episode 601 of “A Growing Passion,” titled “From Fruits to Nuts.”

Prepare the site

  • Deciduous fruit trees, shrubs, and vines require full sun (six-plus hours per day) during the growing season. It can be shady in winter when the plant is dormant.
  • Do a drainage test. Dig a hole 2 feet wide by 2 feet deep. Fill with water and let it drain. Fill again and track how long the hole takes to drain out. If water is gone in a few hours, that’s fast-draining soil. If water sits for a day or two (or longer), that’s slow draining soil, aka “heavy” soil. The rest is in between. The rootstock should match the drainage.
  • Dig a hole ahead of time to rough dimensions. It’s best to plant bare-roots the same day you bring them home, so the roots don’t dry out.
  • Bring inline drip irrigation to the area so it is ready to finish installing after you plant.

Shop for bare-roots

  • Choose plants with pliable roots that are not too tangled. Roots should fan out wide rather than grow in a circle.
  • Opt for low branches. They make ripe fruits easy to reach.

The nursery will wrap the plant roots in plastic, so the roots don’t dry out. That’s critical, so plant on the same day you bring the bare-roots home.

  • Remove the plant from the plastic and spread out the roots. Notice where the color changes on the trunk — that’s the “dirt line” from when the tree was planted. Mark the dirt line with a Sharpie so you don’t lose track.
  • With grafted plants, there’s a thickening on the trunk above the dirt line. That’s the graft, the point where rootstock and the fruiting wood are grafted together. The graft always stays well above the soil.
  • Cut the main trunk of any trees to hip height. As hard as it may be, it’s the best way to encourage low branches for easy care and easy harvest. It also balances the size of the plant to the size of the rootball. Shorten side branches to one or two buds long.
  • Check the size of the planting hole. It should be wide enough for roots to fit without bending, folding, or crunching; deep enough so once the plant is in the ground, the soil line on the trunk or stem matches the level of the soil after planting.
  • Submerge the bare root in a bucket or trashcan of water to cover the roots while you finish prepping the planting hole. The container should be big enough to accommodate the roots without bending or kinking them. Don’t leave the roots submerged for more than two hours.
  • Once the planting hole is the correct width and depth, toss in a few handfuls of worm castings and fill the empty hole with water and let it drain out.
  • As you plant, refill the hole with native soil only — no potting mix, no compost, no fertilizer — just native soil. Water to settle the soil around the roots.
  • Make a watering moat a foot or two away from the trunk. Add two loops of in-line drip, the first 8 or 10 inches away from the trunk, and the second a foot out from the first loop. You’ll add more loops as the tree grows.

Prune and spray established deciduous fruit trees

  • Prune deciduous fruit trees to stimulate fruit production. Different kinds of fruits (peaches, plums, apples, etc.) fruit on different parts of the branches so each is pruned differently. If you prune them incorrectly, you risk cutting off the fruiting wood.
  • Learn how to prune from experienced gardeners or online information, or look for a good pruning book, like my favorite, “How to Prune Fruit Trees and Roses” by Ken Andersen and R. Sanford Martin.
  • Spray dormant fruit trees now to prevent leaf curl, fire blight, downy mildew, aphids, scale and other problems in spring and summer. Use Liqui-Cop or Daconil fungicides along with mineral-based horticultural oil. Each product should be sprayed three times before the trees start to flower in spring. Follow all label directions.

Citrus

  • Winter is citrus time! Harvest kumquats, Washington navel, Oro Blanco grapefruits, pummelos, Eureka lemons, limes and more as they ripen.
  • Color does not indicate ripeness when it comes to citrus. If your oranges are orange but taste bitter or sour, they’re not ripe. Taste is the best test for ripeness.

Vegetable garden

  • Harvest turnips, rutabaga, carrots, etc. as you need them. When harvesting leafy greens, pick only as many leaves as you need. There’s no reason to pick an entire head.
  • Feed brassicas — cabbage, cauliflower, etc. with all purpose vegetable fertilizer
  • Watch for aphids. Shoot them with a hard spray of water using a Bug Blaster hose end nozzle.
  • Watch for holes and ragged edges in brassica leaves. They are telltale signs of tiny green worms. The leaves may look ugly, but treat only when the damage is so extreme that the plant is suffering. When that happens, use Bt organic pesticide, which is specifically for worms and mosquito larvae. It kills caterpillars, too, so keep it away from passion vines, parsley, dill, fennel, milkweed and other plants that attract butterflies.
  • Let some parsley, dill and cilantro go to seed for an ongoing supply.
  • Pick beans and peas as they ripen.
  • Continue to plant from seed: rutabaga, carrots, beets, turnips, radishes, leafy greens.

Select deciduous ornamental trees and shrubs

  • If you love seasons, plant deciduous ornamental trees and shrubs. They lose their leaves in fall and flower in spring, then leaf out. Deciduous plants whose leaves turn colors in fall:

– Smoke tree (Cotinus coggygria)

– Crape myrtle (Lagerstroemia indica)

– Chinese pistache (Pistacia chinensis)

– Roger’s Red grape (Vitis ‘Roger’s Red’)

– Native black oak (Quercus kelloggii)

  • Plant deciduous trees on the south side of your home for summer shade and winter warming.
  • Match the ultimate size of all plants to the space. Don’t expect to prune trees and shrubs to keep them small.
  • Shape it early. Set trees’ structure and branching patterns with early pruning done by a licensed certified arborist.

Plant ornamental plants

All native and non-native drought tolerant plants are best planted in the cool months.

  • Start small. A 5- or 15-gallon plant grows faster and stronger than one in a larger container. A 1- or 5-gallon shrub grows faster than a larger one.
  • Check the roots. Reject plants with exposed roots, tangled roots, roots that circle the trunk or sit above the potting soil, etc.
  • Plant properly. Set the plant at the same level it was in the container. Loosen up the rootball. Do not amend the planting hole.
  • Water consistently. Unless it rains, new trees, shrubs etc., need to be kept damp (not wet) through their first year or two in the ground. Then, cut back on water.
  • Leave leaves. Despite what your parents said, leaves in garden beds are good. Leaves from ornamental plants (not fruit trees) become mulch. Rake pathways and patios. Everywhere else, leave the leaves.
  • Cover all garden beds in a 2- or 3-inch layer of mulch. Leave a 10-by-10-foot area bare for native ground-nesting bees (they won’t sting you).
  • Plant pooped-out poinsettia in your garden. Choose a spot in sun or shade, where the night sky is totally dark from September to December. The long dark period stimulates next winter’s bloom. Poinsettias like good drainage and little water. Fertilize monthly once daytime temperatures are above 60 degrees (for how-to, see https://agrowingpassion.com/poinsettias-holiday-season/).
  • Keep potted plants damp but not too wet.
  • Prune shrub roses back by a third and remove any lingering leaves. Send away leftover leaves, petals, rosehips and pruned-off branches in the green waste. Plant bare root roses as they come into the nursery.

Houseplants

  • Heating houses dries out the air and that’s hard on many houseplants. So, give your plants a spa day — in the bathroom! Fill the tub with a few inches of water. Prop your houseplants on top of empty plant pots (upside down) or other “props” set in the tub. Allow the houseplants to enjoy the humidity but not sit in water. Leave them for a day or so.
  • Check houseplants for aphids, mealy bugs or scale. Use a cotton swab dipped in alcohol to kill the critters.
  • An inch layer of fine gravel or rounded pebble over the top of potting soil stops fungus gnats from laying eggs in damp potting soil, and soon, they disappear.

Sterman is a waterwise garden designer and writer and the host of “A Growing Passion” on KPBS television. More information is at agrowingpassion.com and waterwisegardener.com.