Winter Protection
Newly transplanted or very young trees and shrubs—or any of questionable hardiness—need special protection against winter severities. Our favorite method for small specimens is to pack salt hay or leaves around them loosely and put an upturned basket on top. Somewhat taller shrubs may be encircled with evergreen branches, the ends being stuck in the ground and tied together over the tops. For groupings of shrubs, we put a burlap barrier on the windward side, especially for tender types, and sometimes make a tent of sorts. Evergreens planted where the late winter sun might burn them need shade of some sort—a lathed frame, snow fence, or the like.
PROPAGATING MINIATURE TREES AND SHRUBS
This is one of my favorite addictions. I can’t resist planting any seeds that come my way, can’t bear to discard an evergreen or a broken branch of cotoneaster, can’t resist the impulse to root cuttings. As a result, our rather small nursery bed is closely populated with small, young shrubs and trees of all kinds. I doubt that we’ll ever find space to plant them once they’re grown; and I imagine I could be rather popular could I ever bring myself to give them away.
Propagating trees and shrubs is predominantly a trial-and-error proposition because each variety has its own preferred method of reproducing itself. Some are difficult to raise from seeds, some won’t propagate any other way; some root readily from cuttings, some take three years; some are amenable to layering, others are not. For me this guesswork is a good thing. If all my seeds and cuttings took root and grew into bushes and trees, there’d be no challenge, no fun, and no place to put them.
We always keep a propagating box handy—a shallow box or flat with sides and top of glass or polyethylene. In summer it rests under a tree; in winter it may be on an unheated porch, in the cold frame, or in the greenhouse. The propagating medium may be Pelonex or perlite; a three-way mixture of peat, vermiculite, and perlite; half-and-half sterilized leaf mold and sharp sand (peat packs too hard for me); or clean sharp sand alone. The medium is kept constantly moist but not soggy and is never allowed to dry out. Cuttings are inserted in rows, and removed for potting as soon as the roots are an inch or so long. Sometimes seed is sown in part of the box, or we may rig up a second box when we have a goodly number to plant. The glass, or plastic, sides and top preserve moisture and keep the air humid.
Seeds
Most types of shrubs and trees are rather slow to grow to maturity from seed. And seeds of miniatures produce all-miniature seedlings only when the seed-bearing parents are natural species with natural miniature characteristics. Small varieties of larger species, “sports” or mutations, can’t always be counted on to produce small offspring.
Seeds vary in the time they take to germinate (three weeks to three years, depending on the plant) and in germination requirements. Some need warmth, some cool temperatures, some darkness, some light. And some need a period of dormancy or “after-ripening” before they are planted. In a process of “stratification” seeds are stored in moist sand for several months, usually at about 40 degrees or slightly less. However, some types (cedar, mugho pine) need to be frozen; a few others are stratified in warmth. Some seeds that you buy have already been stratified. The package will tell you so.
Fleshy seeds, such as chestnuts, are usually planted as soon as they ripen and fall. When seeds are covered with a fruity coat, like holly berries, for example, the berry should be soaked in water for a few days until the seeds can be squeezed free of the pulp. Hard-coated seeds need to be gently cracked, or nicked, to hasten germination, and can be sown outdoors in the fall to germinate the following spring, or even the spring after that. Most winged seeds of conifers need to be stratified (remove the wings) in moist sand all winter at 35 to 40 degrees and are planted in the spring. Fine seeds, as for rhododendrons, can be harvested from the split pods in fall and stored cool and dry until spring.