Bare-root season
| Friday, Jan 06 2012 09:51 PM
Last Updated Tuesday, Jan 17 2012 07:20 AM
It's bare-root season. Deciduous plants (those that sleep nude in winter) are particularly agreeable to cold-season planting. They arrive at local nurseries starting in December and continue into early January. It's one of the best times to acquire rose bushes, fruit trees, and a wide variety of flowering plants.
Before purchasing bare-roots, the first thing to do is to acquire soil amendments and prepare the planting area. I recommend doing the earthwork before buying plants, so the exact number and placement of specimens is certain.
Organic matter should be worked into the soil either with a shovel or a mini-tiller. The Mantis brand of mini-tiller has a patented blade design that really cuts through the soil and breaks up dirt clods effectively. Clay soils in our region are almost always on the alkaline side, and should be amended with gypsite or soil sulphur (the yellow crystalline kind).
Dig planting holes about three times as wide as their depth, so the roots are encouraged to spread. It's not necessary for the hole to be cylindrical; sloping sides are fine. Smaller planting holes are allowed only if the entire planting bed has been tilled and amended. In established gardens mixing amendments with the backfill soil in a wheelbarrow helps keep the process tidy.
When planting bare-root plants, it's important not to leave air pockets in the soil. Add the backfill into the planting hole in three separate lifts (it's sort of like mixing cake batter, adding the flour gradually). After each stage of backfilling, tamp down the soil with the toe of a boot or the handle-end of the shovel, but don't stomp so hard as to damage roots. This assures stable
planting, so the plant won't wobble and loosen roots when it leafs out and gets blown by wind.
Depending on the type of irrigation it may be advisable to build a doughnut-shaped mound around the planting pit to hold water. If the area is level and spray-irrigated this is usually not needed. Overwatering can drown a newly established root system in heavy soil. New trees provided drip or bubbler irrigation may benefit from a soil moat, and those planted on sloping ground should have mounding to prevent irrigation runoff.
Bare-root trees should be staked for support, and some shrubs should be staked temporarily during planting to be sure they stay upright. Depending on the type of tree various staking and support options are available, and it's best to consult with a nurseryman about which is appropriate for a given tree species. A simple plastic-coated metal stake with side-mounted foam brackets works well supporting smaller bare-root trees. Guy wires in a triangle are only used in the highest-wind environments or for weak or sick trees with reduced stability. Don't make the mistake of removing stakes too early unless you want a leaning tree.
Remember that bare-root plants require enough space to grow to maturity. Most rose bushes grow larger in our climate than the breeders describe. A couple -- Northern-European breeders Poulson and David Austin -- list for their cultivars sizes about half of what those roses reach in Kern County.
Careful about cutting
Not all pruning should be done in winter. Deciduous plants are described as blooming either on new growth or old growth. New growth means the new twigs that emerge in spring bear the flowers. Old-growth types set flower buds before going dormant, so the flowers open directly off the previously dormant twigs.
A simple (but not foolproof) way to distinguish between the two is by looking for leaves. If new twigs with fresh leaves emerge and produce flower buds, it's a new-wood bloomer; if the bare stems erupt with flowers before leaves start to grow it's an old-wood bloomer.
The earliest blooming deciduous shrubs, such as forsythia and flowering quince, bloom from old wood, so they are best pruned just after flowering, before much new growth emerges. Stone fruit (peaches, plums, nectarines) also bloom from old wood, so wintertime pruning should be very limited to avoid losing the crop. These trees may be thinned of crossing branches and vertical twigs (called water sprouts), but structural pruning should be done after the fruit is harvested in spring or summer.
Some old-wood fruit trees and bushes are sneaky, and violate the flowers-first principle. Pomegranates, blackberries and raspberries leaf out heavily in springtime yet still yield fruit off old wood. These should be pruned after harvest.
Fruit trees that don't lose their leaves, called broadleaf evergreen fruits, should likewise be pruned after harvest. In Kern County gardens this includes citrus, avocado and feijoa (pineapple guava).
Roses bloom on new wood. The popular Hybrid tea roses with their long flower stems and elongated buds benefit from rather hard pruning. Everything less than an half-inch thick can and should be cut off in December-February, and what remains should be shaped to have an open center for air circulation (in other words, the air space straight up from the middle of the roots should be clear of branches).
After the initial thinning of twiggy growth the hybrid tea canes should be pruned down to about three-quarter inch thickness so each branch has an outward-facing bud near the top. Old brown canes with dull brown thorns should be removed when a new cane over three-quarters of an inch thick emerges near their base. Simply cut the old brown cane off (with a pair of loppers or a pruning saw) a half-inch or so above the new side branch.
Floribunda roses and landscape roses, which produce masses of flowers per stem, are much less picky about pruning. Some rosarians literally cut the whole bush down to perhaps a foot tall (yes, with hedge trimmers in some cases), then thin out any remaining twigs. Miniature roses can simply be cut back by half and thinned slightly.
Roses grow so vigorously in our climate that another step is recommended, but not until springtime. Typically each cane will produce several new branches, some aiming straight into the middle of the bush. These can be disbudded (i.e. snapped off with gloved fingers) when they are still small and reddish. In my garden, the disbudding of interior growth takes quite a while, the downside of having (dare it be said) too many roses.
Richard Shiell is a professional photographer and gardening enthusiast. If you have a question for him, send it to btowngardenwriter@hotmail.com.
