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Q: I know that frequent watering is important for a new tree. But what does that mean? How frequent? I am planning to plant some trees soon.

A: You are quite right. Water is not only important but all-important for a transplanted tree. Even in a wet climate, where most gardening advice is generated, lack of water is the number one cause of tree failure.

Watering around a young tree does not mean waving a hose in its direction. My recommendation is to water every day for the first week after planting a tree, then every other day for the second week. After that, for the first growing season, plan to give a tree five gallons of water every time the top inch of soil dries out. A whole season of irrigating is critical even for native trees because their root systems are not deep and wide enough to stay in contact with ground water.

Mulch around a new tree to help hold soil moisture. Keep at least two feet all around the trunk free of weeds or any large garden plants; they would compete for water.

Q: Why do you say that pruning a tree makes it grow faster?

A: Even though it sounds irrational, pruning does cause new growth in two ways. One is that trees keep a balance between their roots and their branches. When branches are cut back, too much is left underground for what is on top. The tree immediately starts getting itself back in balance by making new branches until its top and bottom are in equilibrium again.

The other factor is that trunks and branches are always full of buds. The buds are invisible, and they cannot grow because they are kept in check by buds at the branch tips. If a branch tip (or a whole branch) is pruned off, those actively growing tip buds have been pruned off, too. The chemical balance in the tree is changed. Buds which were held in suspension are permitted to grow, and they do.

Usually the buds closest to the pruning point are the ones which become dominant and are free to grow. They develop into new branches. At the same time, those same buds begin chemically to suppress the growth of other buds closer to the center of the tree, as well as those closer to the ground. The chemical permission for buds to grow only near branch tips explains the basic shape of trees.

Q: I planted some clumps of ornamental grasses a year ago and never cut them back, even when I cut down my perennial flowers. Do I have to do something with the grasses this spring? Some still look fine, but some others are looking tired.

A: I recommend that you cut down all of last year's grass stems now. This year's growth will be starting by the end of this month. Afterward, it will be hard to remove last year's stems without breaking or cutting the new ones. Pruning ornamental grasses is a significant piece of work. On the other hand, it is the only maintenance that grasses require, so one annual job still means that grasses are undemanding garden plants.

If you do not want a number of cuts on your hands from sharp leaf edges, wear gloves for grass pruning. To avoid a mess of scattered stems to clean up, there are at least two possibilities. Hold a small bunch of stems with one hand while cutting them with the other, and dump the cut bunches into a large tub or bag which you have thoughtfully brought with you. Or especially if a grass clump is several years old and consequently large, tie the stems in a bunch before beginning to cut. With really large grass clumps it may be necessary to tie several bundles.

Some gardeners prefer to tie grasses with a bungee cord. When the whole bundle is cut loose, it can be carried to the compost. The cord is then free for operating on the next bundle. Other gardeners prefer first to tie all the grass in bundles with tape, then cut all the bundles and carry them to the compost all at once. For bundles tied with tape, masking tape is the best choice that I know of. It can be left in the compost pile to disintegrate along with the grass. Since masking tape is notoriously weak, each bundle may need two or three ties. Usually grasses are cut four to six inches above the ground, just above the bottom, where stems are too dense to cut. The base should be left to protect the crowns.

Various people use various tools on the grass stems. I know of none that is perfect. Favorite tools include pruning shears, garden shears, grass shears, pruning saws, hedge clippers, and a string trimmer with a blade instead of a nylon string. There are even long-bladed garden knives designed for sawing through grass stems. Try to get the job done before this year's new growth is mangled in the operation.

Q: When should I fertilize bulbs?

A: Spring is a good time. They need fertilizer only once a year, but the leaves have just a short time to feed the plant before they turn yellow and go dormant. Give them food as soon as you can see where they are.

Imported Seeds

I have recently begun to understand a disadvantage that can come to gardeners because of the global economy. Commercial seeds for home gardens may be grown at many places in the world these days. In some of those places days are shorter, rainfall is greater, climate is generally more benign than summer in Montana. As a result, those seeds are adapted to an ecosystem quite different from the one they will meet in a Montana garden.

We have all known for years that native plants grow best if they spring from native seed. Seeds gathered even in eastern Montana will not grow into the same plants as those from western Montana seed. The same thing appears to be true with vegetables. I have been scratching my head about tomato plants which grew less well in recent years than five years ago. Then I noticed some plants, supposed to be dwarf container varieties, which grew very tall. When I looked at the seed source, some came from Thailand, some from China. That is a radically different climate; the variation from one side of the Rockies to the other is miniscule in comparison.

This is pure speculation, with no experimental evidence to confirm or deny. I think that seeds grown half a world away in a different climate may not do well in local gardens. I think that the vegetables which grow from those seeds may not be able to adapt here. I suggest that gardeners check seed origin whenever possible and see whether it coordinates with the quality of a vegetable. There are always variables to consider, and the weather varies from year to year, but seed origin may be one more variable.