Be careful how you prune blue spruce

Q. I have a couple of blue spruce trees. Someone told me to trim the bottom two layers of branches that are touching the ground. Is this a common practice/procedure and/or is there any benefit to the trees?

A. This is not necessary for the health of the tree but is often done to improve access around the tree or to grow grass beneath it. Removing lower branches on mature trees also can result in unnecessary large wounds.

You should, however, remove any dead branches and diseased branches to limit the spread of disease. Make cuts flush with the branch bark collar when removing branches. This is the swollen ring of tissue at the base of the branch.

Disinfect tools between cuts when pruning out diseased branches. Dip tools in a one-part-bleach-and-nine-parts-water solution, 70% alcohol or a disinfectant spray. Clean the pruning tools after pruning to avoid damage from the bleach solution.

Q. We have a 2-1⁄2-foot-wide and 20foot-long area on the south side of our house, right next to our driveway. I usually plant moss roses there and they do well. I would like to try something with height. Are there grasses that would stay upright, with some color, that like heat and don't need deep soil?

A. I assume the area receives plenty of sunlight, given that your moss roses do well. How about trying a mix of several different grasses and perennials suited to these growing conditions? This will provide an attractive display and diversity in case a disease or insect attack the garden.

Blue fescue grass is heat-, drought- and salt-tolerant but struggles in clay. It grows about 12 inches tall. Blue oat grass is taller and with wider leaves, and I find more tolerant of our clay. Both have blue green foliage.

Feather reed grass and Shenandoah switchgrass are much taller at about 4 feet and tolerant of these conditions. Walker’s Low catmint has gray foliage and blue flowers. Just cut

it back once midseason if it starts looking unkempt. Calamintha nepeta nepeta has light airy white or blue flowers and grows 1 to 1 1⁄2 feet tall. And no, this was not a typo; you want the the C. nepeta nepeta to avoid excessive self-seeding.

Sedums, yarrows, butterflyweed, penstemon and Zagreb threadleaf coreopsis are also good choices.

Look for perennials that are listed as droughttolerant, but provide adequate moisture the first few years to get them established. And consider mulching the soil with shredded leaves or evergreen needles to conserve moisture and keep the roots cooler during the heat of summer. If the area is subject to deicing salt, be sure to water thoroughly in spring. This helps wash the salts through the soil and away from the plant roots if we do not have adequate spring rains.

Q. I just bought a marble queen pothos and want to put it in a pot and in the middle add Aglaonema (Chinese evergreen) for a beautiful design. Would this work? They both require the same light soil and watering, but I’m a little scared to try it without knowing what will happen.

A. This would be a beautiful combination. You are wise to look for plants that tolerate the same growing conditions and have similar growth rates when planting them in the same container. The biggest mistake I see is planting too many plants that quickly outgrow the small container. Plus, some are faster-growing than others, resulting in one or two big plants and several puny stressed specimens. These must be divided and moved to their own container where they can continue to grow and thrive.

Your combination should work well. Just be prepared to replant it in several years if they outgrow the original pot.