As the 2019 garden season begins in Sonoma County, here's a guide for new plantings

On the winter solstice on December 21, the 2018 gardening year died and the 2019 season was born. That's why your mailbox is chock-a-block with gardening catalogs, the seed displays will be refreshed in the nurseries, and bare-root fruits and vegetables will be available at garden centers and over the internet.

Most of the bare-root vegetables are perennial crops, except for members of onion family. You can take potluck in terms of varieties with onion sets you'll find at garden centers, but there's a wider and better selection at mail order suppliers. One I've used successfully for years is Dixondale Farms in Texas.

Right now they'll be shipping starts to our part of the country. These aren't the dry tiny bulbs sold as sets.

Starts are small onion plants that you slip into holes in the soil made with a little finger or pencil, and that swell into full-size onions as the sun waxes toward the June equinox.

Strawberries are sold as bare-root plants now, too. They'll come as a bundle. Disentangle each plant and spread out its roots. Trim any broken roots or broken ends.

Dig a hole in good garden soil about six to eight inches deep and make a mound of soil in the center. Place the plant on top of the mound and spread its roots out down all the sides of the mound.

The crown - the growing point - should just be at our just slightly above the soil surface. Fill the hole with compost and soil and firm it down, then water the plants in.

Make two rows three feet apart of plants a foot apart. As the plants grow in the spring, guide the strawberry runners into the three-foot empty space and pin them to the bare soil with clothes pins or a bit of broken branch.

They'll take root there. The two rows you planted will produce berries this year, while the center area of runners will be new plants for next season's berries.

At this time of year next January, dig up those previous older two rows and toss the plants on the compost pile. The center area where you placed the runners will bear the new year's berries.

And as they in turn produce runners, you can guide them to the empty spaces where your original rows were planted. In this way you keep your berry patch young and fresh, which gives you the most berries.

Asparagus can be an expensive purchase at the supermarket, so why not put in an asparagus patch? They're perennial and will return year after year if you treat them right.

What you're after with asparagus is large, thick spears. Each asparagus spear has the same amount of tough fibers running its length, so the slenderer the spear, the more tightly the fibers are packed and the tougher it is.

Plant scientists have shown that the larger the spear, the farther apart the fibers are spaced, and the interstices are filled with tender flesh.

So, how do we get large spears? Again, plant scientists tell us that plants should be placed in trenches a foot deep and two feet across.

Soil should be mounded in a ridge down the center of each trench two inches high. Bare root plants should be placed on this ridge so their roots run down each side of the ridge in a spread-out pattern.

Plants should be spaced two feet apart in the trench, and a patch should consist of 10 plants per trench and two trenches set seven feet apart. These dimensions produce the most spears of the largest size.

The plants should be in full sun. The soil must be well-drained, as the roots will rot if they stand in water for more than a couple of days.

When back-filling the holes after planting the roots, mix sand and compost liberally into the soil, and don't compress the soil - leave it loose and friable.

The sand helps with the drainage, and asparagus likes a lot of nutrition. Mulch the soil with at least six inches of compost yearly, three inches in the spring before spear production begins, and three in the fall as the bed goes dormant.

Here's an important rule: Don't harvest spears until the third year after planting.

The plants need those first two years to build up resources and make a strong root system. If you harvest during the first two years, you'll damage your bed and it won't recover.

Rhubarb is sold bare-root now. Remember - it's only the red stalks that are edible. The leaves and roots are poisonous. For each root, dig a hole 3 feet in diameter and 1 foot deep.

Place the rhubarb root in the center with the crown at or just below the soil surface. Back-fill the hole with compost, but, as with asparagus, don't compact the soil.

Horseradish is sold as a root now. It's best grown in a large pot in good compost to contain its vigorous growth. It's easy to harvest a piece of root, and it's likely you won't do that too often due to its intensity.

Finally: artichokes. The bare root grows a fine-looking, spiky-leaved plant the first year, but it's only in year two that you start getting chokes.

When you receive your roots, they will look like amorphous chunks, but a little inspection will reveal where the previous stems were cut and where the roots were trimmed.

Dig a hole in rich garden soil about eight inches deep and pop in the root, stem side pointing straight up. Back-fill the hole with compost and soil mixed, and firm in in, then water. Easy as pie.

If you get your bare-root vegetables but can't get to planting right away or it's raining, heel them in. That is, put them in a big plastic pot with drainage and cover them with moist soil. They'll keep fine that way until you can plant them in the garden.

Jeff Cox is a Kenwood-based garden and food writer who can be reached at jeffcox@sonic.net.