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Depending on the perennial, if it is starting to show some growth, dig it up as soon as you can work the soil, and then divide and transplant. That said, another approach is simply to do it when you have the time and before you get too busy with other garden chores.

April, during spring clean-up, is one of the better times to divide and move perennials. During the growing season, gardeners are busy monitoring for pests, diseases, deadheading, and watering against the heat. Dividing in the spring allows the plants to grow to their new space, you to see if the placement coincides with your vision, and lets you enjoy them in their new location. Those plants you don’t get to in the spring, then divide them in the fall.

Horsetail (Equisetum) should be admired for its tenacity as a living fossil. Virtually unchanged for millions of years, it thrives in those early prehistoric conditions: moist and boggy, or compacted and lean. Blessed with underground rhizomes, every time you pull or dig, any little piece resprouts a new plant. Black plastic smothering only gives them the oxygen-starved conditions they love. Applying heavy shredded mulch also provides the same moist, airless blanket.

The key is to change the soil conditions it prefers. Take a hard look at the garden bed affected. First, tackle poor drainage. If needed, add a perimeter ditch around the bed to drain water away from the center. If that isn’t possible, you may need to add a length of field drain to divert the water farther away from the bed.

Temporarily remove any mulch and apply dolomite lime at the rate recommended on the package for the square footage. Wait 2 weeks before amending the soil since lime and organic enrichments can conflict. Water in the lime so that it penetrates. Then determine where the low spots are and build them up with enriched compost, such as aged cow manure, leaf litter, or a balanced blend of organic compost.

You should see significant improvement in the first year, although you will see a few horsetails. Changing the soil conditions to those least preferred appears to send an evolutionary signal to cease and desist. To prevent reinfection, watch in April for the leafless fertile stems that contain millions of spores. Cut them off, put them in a ziplock bag and dispose in the garbage, not yard waste.

Contrary to popular belief, evergreen needles do not stay green forever. The older, inner needles discolor and naturally drop off after one or more years. Yew needles turn yellow and drop in the late spring or early summer instead of the fall, like their deciduous counterparts. If that is the location of your yellow needles, then it is a natural process to get rid of old interior needles and sprout fresh ones.

If the yellow needles are on the tips or outer branches, that can be a symptom of another cause. If yews are sheared late in the season, any resulting new growth does not have time to harden off before the temperatures drop. The tip tissue is killed and the result is yellow or browning in spring.

Another reason yews begin yellowing is too much water. They don’t like wet feet or sitting in poorly drained situations (such as near a downspout). Often planted by walkways and driveways, they can get an abundance of snow load or rain run-off, which does not drain quickly due to the surrounding hardscape. They are also sensitive to de-icing salts. Poor drainage, soggy conditions and salt damage can cause root rot, which is a fungus that girdles the roots, strangling the cambium and preventing water and nutrients from reaching the outer branches.

So check the location of the yellow needles. Then check the location of the plants themselves. It may be a natural seasonal process or something that warrants a physical remedy.

Most weeping tree varieties are grafted, and therefore, that is their most vulnerable spot. Southern exposure can be great,

except in winter when the sun comes at a lower angle across the landscape. It warms the dormant stem and causes the cambium to expand and contract. Because the graft is the juncture of two bonded plant tissues, it is likely the weaker grafted top that will die as a result. The rootstock, being the stronger tissue, will be more exuberant in its efforts to grow.

If you can protect the trunk and graft of a replacement tree with a good winter sunshield, then there are several alternatives to the cotoneaster that can get you the look you want. You could even replace the lost tree with another of the same type.

Two varieties of weeping redbuds (Cercis) will give you that pendulous, mop-haired look: “Ruby Falls” and “Lavender Twist.” The added beauty is stunning pink flowers in spring followed by burgundy heart-shaped foliage.

Another slow grower is a dwarf Japanese maple (Acer palmatum ‘Ryusen’). This has glorious burgundy leaves and brilliant red foliage in fall. If you prefer a conifer, a dwarf weeping hemlock grows quite slowly and would manage well in a container with sufficient moisture. A weeping larch (Larix decidua ‘Pendula’) is stunning with its emerging soft green needles in spring. It has a lacey appearance and is quite durable in winter. The central leader should be staked but it needs minimal care. Another contender is a weeping white pine called ‘Angel Falls.’ It can handle drier conditions, grows slowly, and remains evergreen through the seasons.

By late May, the soil has warmed up sufficiently and the threat of a sudden freeze is reduced. Both evergreens would benefit from this late May time frame for planting. Both would then have all season to establish and set up root systems in their soil base before winter.

When planting, choose a slightly cloudy day and make the hole 2 to 3 times wider than the pot but at the same depth as the pot. Spread out the roots and look for girdling roots to be pruned out. Amend the soil backfill with compost or a little cow manure. Make sure the areas have good drainage, as neither plant likes wet feet or boggy conditions.

That said, spruces and boxwoods do need consistent moisture during the first three years, as they are slow to develop an extended root system. Checking the soil moisture during the season can help you monitor when and how much to water. Also provide water into late fall, as this is the time plants store up reserves. Sprinkler systems are often prematurely turned off for the winter, at the convenience of the irrigation company, leaving the homeowner without a means to deep water evergreens and trees. Lack of water going into winter is a common cause of tree and shrub plant failure the following season.

Answers provided by Beverly Moss, owner of Garden Rhythms.