Q: Should I be pruning my Oregon grape right now, along with my other bushes and trees?
A: Probably not. The various species of Oregon grape seldom need pruning. If you have one of the bushy kinds and it seems to be getting too crowded, prune it as you would any other bush. In other words, thin by cutting any unwanted stems as close to the ground as possible, but do not remove more than a quarter of the stems in any one year.
If your Oregon grape seems to be a suckering type, just cut off any stems where you do not want them to be growing. If your Oregon grape is a ground cover, prune it only if it grows too tall. Cutting stems to the ground will encourage compact and dense growth. Oregon grape is definitely a low maintenance plant.
This plant’s names, both scientific and common, may be the most difficult aspect to learn. Oregon grapes can cross with barberries, and taxonomists are currently not sure whether they are one genus or two. Be prepared to find them called either Mahonia or Berberis. The common name may be lengthened to Oregongrapeholly, Oregon Grape Holly, or Oregon Hollygrape. By any name, they are still those broadleaved evergreens with yellow flowers and blue berries.
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Propagating an elderberry
Q: I have a really nice elderberry. It is big enough to be almost a tree, and the stalks remind me of bamboo. It always blooms, and last year I had berries to give away. I would like to share my elderberry with other gardeners. How do I propagate it?
A: You have three choices. If you want to grow new plants from cuttings, both hardwood and softwood ones root easily. For hardwood cuttings, take tips right now, about six inches long and from branches as thick as a pencil. Be sure that each cutting has at least two buds. Remove the top inch. The standard way to make cuttings like these, where you cannot tell top from bottom, is to cut the top at an angle and the bottom straight across. If you were to plant them upside down, they would never grow.
Rooting hormone is very helpful with cuttings from bushes, since it encourages roots to start. Follow the directions on the package. Stick your cuttings in a container of damp potting soil with a bud above the surface. Cover the container with a clear plastic bag and leave it outdoors. Choose a sheltered place which gets no direct sun. Wait patiently.
You can also wait until the elderberry is growing well this spring and make cuttings from this season’s new green tips. Follow the same procedure as with hardwood cuttings, except that you will not have to worry about planting them upside down. Softwood cuttings will probably root more quickly. Either kind of cutting will be big enough to plant in open ground either next spring or a year later.
The third way to grow elderberries is from seed. Wait until fall to start the process. Leave some of this year’s berries to get overripe and then separate their seeds from the pulp. Store the fresh seeds in damp potting soil or sand, in a plastic bag, for two months at room temperature. Keep them moist but not soggy.
After those two months, move the seed container to a refrigerator. Mark your calendar, because the seeds need a fake winter of three to five months. By that time it will be spring. You can move the seeds back to warm temperatures and germinate them. All of these propagating methods require both planning and work. The recipients of your plants should appreciate your generous gift.
Restoring overgrown fruit trees
Q: We bought a home with some overgrown old fruit trees. How do we go about restoring them? Or do we have to cut them down and start over?
A: Don’t cut them down, but don’t try to restore them all at once. If you prune the trees into shape this year, you will shock them into growing a whole forest of shoots. Then you will have to deal with all those watersprouts.
Instead, plan to take four years to get those old trees into good shape. This year, do the normal first step of pruning: take out all the dead, damaged, and crossing branches. Then remove a quarter of the healthy branches which are left. Choose for elimination those which seem to be misplaced or which are not going to be productive. Any branch which grows straight up is a good candidate for removal.
Your trees will respond to the unaccustomed pruning by starting a lot of watersprouts. If you have time this summer, remove them by rubbing them off as soon as they get started. You will recognize incipient watersprouts as buds sprouting along the tops of branches. Leave a watersprout only if it is in a position to make a replacement branch. Keep looking at the shape of the tree as you work, imagining where a new branch would look good.
Whether or not you manage to remove watersprouts this summer, you will want to finish the job a year from now, cutting off the remaining ones. In this second year of renovating old trees, you can also shorten any branches which are too long. Remember to cut at a fork, leaving no stub to die.
In the third and fourth years, continue to thin the canopy by taking out a quarter of the old branches. By then you will know which are the unproductive ones. Also remove long young stems. By the end of the fourth year, the old trees should be shapely and productive. You will have progressed to routine yearly pruning.
One way to grow new plants is from seed. Any seedling has inherited a mix of characteristics from its parents. It will grow up to be like them, but not identical. Cuttings produce exact copies of the plant from which they came. Those new plants may be started from a leaf, a stem, a root – from any part of a plant which is capable of growing both new roots and new stems. Different plants have different abilities. Not many plants, for example, can grow a whole new plant from a leaf, the way that African violets can. Only some plants, like Oriental poppies, can grow a new plant from a piece of dormant root.
More recently, horticulturists have developed techniques of micropropagation. They persuade single cells growing in a sterile broth to produce whole new plants. This ability to grow many, many new plants at once makes the new plants inexpensive. Orchids are a good example. Once grown only by the wealthy, orchids produced from tissue culture are now the most popular house plants in this country.
The ability to reproduce themselves from parts means that some plants are very, very old. Your Christmas cactus which came as a cutting from your grandmother’s plant may be a century old. Antique garden plants grown from rhizomes or runners may be a thousand years old.
Plants which reproduce without human help are even more ancient. Some grasses, for example, can spread indefinitely from underground rhizomes. On undisturbed prairie there may be grass plants which have been quietly propagating themselves ever since the last Ice Age.