A good time to prune ornamental grasses, plant trees and shrubs

Written by Jennie Hagen May 03, 2011 03:50 pm
If you have not pruned your ornamental grasses back, it needs to be done as soon as possible.

Irregardless of the size of the grass I am pruning, unless it is too large to get an arm around, I have found the fastest and most attractive way to prune is to simply gather the entire plant, this includes all stems, even those that have fallen over and are laying on the ground, pulling them up into a “pony-tail” and shearing them straight off. When they fall back into place, they form a natural-looking clump that is slightly rounded, giving them a finished and tidy appearance.

After this I comb the plant with my fingers, pulling straight up with slight pressure, to remove most of last year’s dead stems. Always wear gloves. Many ornamental grasses can have quite sharp stems. I pruned mine about three weeks ago and even with this cold weather the new growth has already surpassed the pruned mark.

Now is also a good time to plant trees and shrubs. And although our spring weather has been exceptionally cool and wet, new plantings need to be watered thoroughly when placed in the ground and at least once a week thereafter until established and new growth is vigorous. We planted some about two weeks ago and were surprised to discover Sunday they were completely dry — not just on the surface but several inches down as well.

Don’t forget to place a dike around your new plantings. It keeps the water where you need it and does not just allow it to run off.

A dike circling your plant should be the size of the width of your plant, so if your shrub is two feet wide, the dike, or donut-shaped ring, should be that wide as well. This allows for any natural rainfall or overhead watering to be captured within the drip line. As a general rule, most trees and shrubs will not have roots that extend further than the plant is wide, sort of a natural way for the plant to receive the most benefit from rain. Most trees and shrubs purchased at local nurseries are already acclimated to our area. This is one reason why you will notice they are not fully leafed out yet. Don’t let that bother you.

Look along the Grande Ronde River. Note the cottonwood trees aren’t open yet. Drive to Pendleton and you’ll discover the cottonwood trees along the Umatilla River are green and thriving. So don’t let planting dormant-appearing trees or shrubs deter you from purchasing them. Anything planted now that is fully open may get nipped hard by frost. Observing native habitats can give us a clue as to when to plant.

Locals usually have a time-tested recommendation for planting your vegetable patch. If, when you hold your hand at arm’s length and place your thumb clearly over Mount  Emily, if your thumb covers all remaining snow, go ahead and plant — it should be safe.

Until next time, go out and play in the dirt. Horticultural therapy is the best remedy to beat the winter blues and lift your spirits!


Jennie Lu Hagen is a La Grande gardener.