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  • Waterwise Gardening | David Salman

Garden Tips for mid-April 🌼

We're experiencing a mild, dry spring and our plants are waking up a little early. So it's very important to begin more regular watering. Soak perennials and smaller plants once weekly. So go ahead and get your irrigation system ready, cut back your plants to remove the dead foliage from last year’s growing season and prune your summer-blooming shrubs. It’s also time for soil care; feed the soil and mulch. And keep an eye out for critters that want to make your yard their personal cafeteria.

Be sure and mulch your plants with a thick layer of gravel in xeric gardens or put down pecan shell mulch and other non-mineral materials at least 2" thick around trees, shrubs and flower beds. It will be important to keep the ground as cool and damp (after irrigating) as possible.

Now that it's April, it's time to cut back our perennials

Herbaceous perennials

If you haven't already done so, cut off 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.

Now is the time 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 hard in mid-spring. Big growers should be left with about 4" of stubble and smaller growers should be left with about 2" of stubble. It's essential that the old stems be roughed out with gloved hands to remove dead stems from the crown and leave room for new foliage to emerge.

Cool season grasses, like Blue Avena Grass (Helictotrichon), Fescue grass (Festuca, pictured left), Silky thread Grass (Nassella) and 'Karl Foerster' Feather Reed grass (Calamagrostis) have evergreen or semi-evergreen foliage.

Don't cut them back hard to the ground like warm season grasses. If there is a lot of dead leaf blades in the clump, it's best to comb them out with gloved hands or a sharp blade. Or, if most of the interior part of the clumps are green, prune off the dead tips leaving the clump dome-shaped, not with a flat top cut.

Dividing Mature Ornamental Grasses

Most ornamental grasses naturally die out in the middle as they mature. The healthy crown and stems tend to grow a

round the edges. So it's very beneficial for the appearance and health

of your ornamental grasses to divide them once every three or four years. Dig up the clump, slicing down right along the edge of the stems growing out of the ground. Cut the big clump into quarters and with gloved hands remove dead stems and roots until you are left with sturdy pieces of living stems and crown. Work compost and Yum Yum Mix into the hole where the grass was dug up and replant the pieces into the hole. Or take some of the pieces and replant them elsewhere.

Here is a warm season ornamental grass (completely brown and dormant) needing division. You can see the lighter brown grass that's still alive growing around the dead, darker brown stubble in the middle.

Get Your Garden Clean-up Done in April

Spring Blooming Deciduous Shrubs, Trees and Fruit Trees: If these plants are blooming or starting to leaf out, The time for hard pruning has passed. As a general rule of thumb, once the leaf and flower buds begin to swell, the primary pruning season is done.

Summer blooming shrubs

  • Native Salvia ( Raspberry Delight, 'Furman's Red, 'Maraschine' and other S. greggii and microphylla types) have started to push new foliage from their woody stems. Remove all wood above the new foliage and shape the plants into a dome. Also, thin out interior branches to clean up the lower main stems. Top-dress the soil around your newly pruned plants with some compost and Yum Yum Mix. I mix 1 part Yum Yum to 2 parts compost. This will provide essential nutrients for them to grow back vigorously and bloom plentifully.

  • Lavender (Lavandula) – I've cut my lavender back hard this year, removing the top 1/3 to 1/2 of the plants. Also, top-dress your lavender plants like the Salvia above.

  • Rosemary should be cut back to remove winter-killed branch tips. Also, prune into a dome shape and thin interior branches along the main stems. What a wonderfully fragrant task!

  • 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.

Turn On and Check Your Drip System for Leaks

By late April, it's time to turn on your drip system. Late, light freezes possible through the middle of May will not cause damage to your drip system. Turn on each zone and walk your landscape to find any leaks or damaged tubing. Gophers love to chew through the pipes and can cause major leaks. Do the walk-through before you apply fresh mulch as it's very difficult to find leaks when the emitters and tubing are covered.

Keep Watering New Spring Transplants Deeply Every Couple of Weeks

  • Keep up with the regular watering of young trees, shrubs, vines and perennials for at least 2 or 3 growing seasons. Under-watering younger woody plants will stunt their growth. Even xeric native trees and shrubs will make better landscape specimens with regular watering to get them well established and larger in size. Then the watering frequency can be decreased over the following years.

  • If watering by hand, be sure to re-build their wells (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.

Feed the Soil Before Mulching

Note: April 14, 2021, We're having supply issues with our Texas supplier of Yum Yum Mix and Back to Earth Blend. We hope to get our shipment soon but we are also working on having suitable substitutes for our customers. We apologize for the inconvenience.

Spread a Yum Yum Mix / high-quality compost blend onto the soil’s surface before spreading the mulch. I recommend one part Yum Yum Mix to 2 or 3 parts good quality compost.

It's a good time to thicken up your existing mulch or cover new areas.

Spread the mulching material to make a good 1 to a 2-inch thick layer. By thickening up the mulch layer, this will ensure that the sun and wind don't evaporate the moisture and leave it in the soil for the plants to use. Also helps to control weeds and slowly enrich the soil.

  • Don’t forget to replenish your gravel mulch. Freezing and thawing of the soil pulls the gravel into the soil and thins the gravel depth on the surface. So thicken it up each spring.

  • Mulching fruit trees heavily will help to keep the soil colder and delay early flowering somewhat. It also helps to control grass around the tree which eliminates grass root competition and increases the tree’s growth.

Protect Plants from Critters

Control Gophers

Gophers have always been a problem in northern NM. But the mild winters of the past 5 or so years seem to have allowed them to increase their populations. And they are especially active in the spring. So, it’s critical that you protect both new transplants and established plants from getting their roots eaten.

  • New transplants – sprinkle a handful of Chase Mole and Gopher Med granules around the base of each plant at planting time and soak the ground to move the emulsified castor oil into the soil.

  • Established plants – watch for mounds of fresh soil and treat the area with the Mole and Gopher Med. Water in thoroughly.

Hungry Deer and Rabbits

New transplants, even rabbit-resistant species like Penstemon and Salvia should be sprayed with a deer and or rabbit repellent at planting time. Repeat one more time until the plants start to grow new foliage.

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