It's heating up! In northern areas of the country, there's something bordering on spring finally happening. In more southerly climes, it's just about summer--in temperature anyway. Now is the time to perform some basic shrub care to keep plants healthy and growing.
Here are some tips for proper shrub care.
Hand-Pruning vs. Shearing/ Hedging
There are a few ways to prune a shrub. We're going to focus mainly on shape in this post. (Renewal pruning one type of pruning that you would do to rejuvenate an older shrub, but that's not necessarily a "seasonal maintenance" type of pruning.)
Spring is a good time to hedge shrubs. You use hedge trimmers (pictured, left) to shear or hedge. With this tool you can clip large numbers of thin branches at the same time. You'd trim an evergreen boxwood hedge with this type of tool. Hedging and shearing works best for evergreens with smaller leaves. It is not an ideal type of pruning for deciduous plants because they end up looking boxy and bare. Evergreens with large leaves can look ratty if sheared because the shears can chop the leaves in half.
When hedging shrubs (whether with a power hedge trimmer or hand shears), point the shears down and away from you. Never hold them above your head! Hold the shears at a slight angle so that, after trimming, the bottom of the shrub is slightly wider than the top (a pyramid shape). That will ensure that light reaches all parts of the shrub and will prevent dieback from the bottom up.
Deciduous shrubs respond better to hand-pruning with loppers (pruners with long handles) or hand pruners (pictured, right). Use hand pruners to keep azaleas looking tidy. Grab a branch that is growing out of bounds and cut it back to the center of the shrub. That will allow the other branches to cover up the pruning cut. You can cut back to almost the center of the shrub or cut back slightly inside the outer leaves--just so you don't leave a shaggy end sticking out.
Here's another picture of hand-pruning for shape:
Prune any spring-blooming shrubs after they bloom. Azaleas, flowering quince, forsythia, and other early bloomers flower on old growth, which means they will set flower buds for next year this fall. If you want to control the size of these plants the time to prune is now.
It's starting to get warmer which means you need to pay more attention to watering.
When you first plant a shrub you'll have to water a little bit every day. That's because the smaller root hairs are regrowing and re-establishing themselves. After a couple of weeks you will be able to cut back to watering deeply a few times a week. Always direct the water at the base of the plant, not on the leaves. Wet leaves are an excellent breeding ground for fungal and bacterial diseases.
Put a fresh layer of mulch down around your shrubs this spring to keep their roots cool and protect them from string trimmers and mowers.
Never make a mulch volcano! Pull the mulch away from the stems of the shrub. A three inch layer of mulch is enough to keep the roots cool and moist.
Most shrubs don't require deadheading but if you remove the spent flowers from rose bushes, butterfly bushes, hydrangeas or other reblooming shrubs, you'll get more flowers and the shrubs will stay tidier.
When deadheading roses always cut back to just above a leaf with five leaflets, ideally a leaf with a bud that is on the side of the shrub facing out.
Spring is also the time to fertilize spring-flowering shrubs such as azaleas and rhododendrons. Those are acid-loving plants that will respond well to fertilizing with Holly Tone or another formulas specifically for plants that grow well with a lower soil pH.
If you have hydrangeas that you want to bloom blue or pink, this is a good time to add lime (for pink blooms) or aluminum sulfate (for blue flowers). (It can take awhile for the pH to adjust.)