Historically February is one of Colorado’s snowiest months, and finally we’re beginning to see evidence of that this year! Additionally, the forecast indicates more to come. It remains to be seen how some of our marginally hardy garden plants have suffered from the below zero temperatures.
Many of us may have the tops of ornamental grasses and various perennials peeking out of the blanket of the snow, which provides habitat for overwintering beneficial insects and it helps to keep the plant roots and crowns warmer. But very soon it will be time to cut back Cool-Season ornamental grasses before their active growth begins, which will allow light to penetrate the entire clump. See Eve’s instructions, below.
Last fall we shared information on the three main types of grasses: cool season, warm season, and evergreen. In addition, we profiled some of our favorite grasses in each grouping. Read the article.
Each season we add new and interesting grasses for your garden, and this year will be no different. Some of our debut grasses include:
Harpochloa falx ‘Compact Black’ (Compact Black Caterpillar Grass)
Heirochloe odorata (Sweet Grass)
Eragrostis spectabilis (Purple Love Grass)
Bouteloua dactyloides (Buffalo Grass)
Muhlenberghia montana (Mountain Muhly)
Sporobolus cryptandrus (Sand Dropseed)
Following are instructions on how to best cut back your ornamental grasses
Cut down cool-season grasses in February, before spring growth resumes, leaving about 2” to 3” of the previous year’s growth. This will prevent tearing the leaf-tips of the new, early growth, and will admit light for the new growth to flourish.
Wear gloves and long sleeves, and use sharp hedge-shears, a scythe, or a power hedge trimmer, and try to make a level, flat cut. Blue Avena, Mexican Feather Grass, Blue Fescue, and some Sedges (Carex species) are evergreen or semi-evergreen and should not be cut down (dead blades can be ‘combed’ out with fingers or hand-rake). Even in a meadow setting, consider mowing or scything the grasses to simulate the effects of wildlife hoofs and foraging, which have benefits for the soil and the plants.
Cut down warm-season grasses in early April, before new growth begins as above, close to the ground (to 3 – 4”). Wear gloves and long sleeves and use sharp hedge-shears, a power hedge-trimmer, or a scythe.
TIP: Before cutting down a clump grass, especially a large, thick one, wrap and tie the clump tightly with twine or a bungie cord 1- 2’ above where you will cut. This will reduce the clean-up considerably. You may also want to enlist the help of a buddy to hold the clump as you cut it.
(The photos below illustrate this technique, typically utilized with larger grass clumps.)