April Garden Clean-Up Tips
Spring has sprung. The apricot and flowering plums are already blooming around Santa Fe! For the most part, the frosts have been very light and their flowers seem undamaged. It is time to get your spring clean-up under way.
Turn On and Check Your Drip System for Leaks
It's time to turn on your drip system. Light freezes typical in April and early May will not cause damage to your drip system. Turn on each zone and walk your landscape to find any leaks or damaged tubing. This is very important because, once you apply the mulch so important for protecting soil moisture, it's very difficult to find leaks that waste precious water.
Keep Watering Deeply Every Couple of Weeks
Remember to water every couple of weeks. This is especially important for any new plants that you transplanted in the past couple of years. Young trees and shrubs should have their wells reformed (small mounds of soil that ring the base of the plant to hold water). Then fill the well a couple of times to soak the soil deeply. The general rule of thumb when it comes to watering is;
Water deeply but less frequently so the roots will follow the water down more deeply into the soil. Shallow, frequent watering encourages shallow roots.
Now is the time to thicken up your existing mulch or cover new areas. Spread the mulching material a good 1 to 2 inch thick layer. By thickening up the mulch layer, this will insure that the sun and wind don't evaporate the moisture and leave it in the soil for the plants to use. This year, it will be essential to use more mulch, especially on younger, less established trees, shrubs and flower beds.
Mulching fruit trees heavily will help to keep the soil colder and delay early flowering somewhat.
Control Noxious Cheat Grass Now !!!
Check your landscape, to see if you see a flush of young green grass sprouting up under Rabbit Brush (Chamisa) bushes, elms and other shady/partially shady areas. Most likely, this is Cheat Grass (Bromus tectorum), a highly invasive non-native grass from western Asia that has overtaken the western US. It's an annual grass that goes to seed in May and dies by late June. But it leaves behind showy but horrible seed heads that can puncture the skin and penetrate the eardrums of our animals causing great damage and pain. This plant is also highly flammable and creates extreme fire danger once the grass dies leaving behind lots of biomass (seed heads and dead foliage).
There are good natural herbicides, like Phydura Weed Killer Spray, that use non-toxic plant extracts and oils to burn back and kill annual weeds. Check local nurseries or go online to locate these herbicides. Spray the young Cheat grass plants in April to kill them before the go to seed.
Get Your Pruning Done Now!
Deciduous Shrubs and Trees: The time for hard pruning of shade, fruit, flowering trees and spring blooming shrubs has past if already in bloom. As a general rule of thumb, once the leaf and flower buds begin to swell, the primary pruning season is done.
Summer blooming shrubs like Russian Sage (Perovskia), Blue Mist Spirea (Caryopteris) and Butterfly Bush (Buddleia davidii and hybrids) can be cut back now in April.
+ Russian Sage should be cut back hard in mid-spring, leaving stems 12-15" tall. This should be done every spring to keep them blooming heavily. This is also the time to dig "suckers" (new stems to push up from the ground) so to keep your Russian sage in bounds and not overtaking its neighbors.
+ Blue Mist Spirea and Buddleia davidii should be cut back by 1/3 to 1/2 of their height every third year (NOT annually) to re-invigorate the shrubs and encourage blooming.
Mid-spring marks the time to cut them back. It's best to wait until mid-spring to cut grasses back. There are two categories of grasses; cool season and warm season growers. They are handled differently during spring clean-up.
Warm season grasses include Little Bluestem (Schizachyrium), Big Bluestem (Andropogon), 'Blonde Ambition' Blue Grama (Bouteloua), Muhly (Muhlenbergia), Prairie Switchgrass (Panicum), Chinese Maidenhair Grass (Miscanthus), Giant Sacatoon (Sporobolus wrightii) and others. They should be cut back in mid-spring. Leave about 2 to 4 inches of stubble standing; big growers should be left with about 4" and smaller growers should be left with about 2".
Cool season grasses, like Blue Avena Grass (Helictotrichon), Fescue grass (Festuca), Silky thread Grass (Nassella) and 'Karl Foerster' Feather Reed grass (Calamagrostis) have evergreen foliage that should not be cut to the ground. Instead vigorously "comb out" dead leaves with gloved hands and clip off the dead leaf tips. In early to mid-spring, clip off old seed head stalks as far down into the foliage as possible to leave room for late spring flowers.
Now that it's April, it's time to cut back our perennials.
- Herbaceous perennials that have dead, above-ground stems and leaves. In general, these perennials will show you where to cut . Look for a low mound of new foliage at the base of the old dead stems and cut off these dead brown stems just above the new green foliage.
- Evergreen perennials like Lavender, Rosemary, Beardtongue (Penstemon) and others, only need to have winter killed stem tips and leaves removed. Don't cut back evergreens to ground-level like their herbaceous neighbors. This will injure or kill these evergreens.
- Lavender (Lavandula) - to get these important ornamental herbs ready for the new growing season, I recommend waiting to cut them back until you can see tiny green stems beginning to push out from the old woody stems. This will show you how much of the old branches have been damaged from winter cold and desiccation. Shear the plants to remove the dead branches just above where the upmost new growth is emerging from the old stems, to leave a nice rounded mound of stems and foliage. Remove old dead foliage in the plant's interior by roughing them up the stems/leaves with gloved hands.
- Beardongue (Penstemon) - Cut back the old flowering stems and lanky stems to leave a nice mound, rounded mound of the evergreen leaves and stems. This will re-invigorate the plants and make the flowering stems more even.
- Other evergreen perennials - simply remove winter killed stem tips and foliage to leave a nice mounded plant.