8 steps to successful planting in the mountains
We have terrible dirt to work with in tri-city yards and gardens. But if we choose the right plants and work to improve the soil, we can create great-looking landscapes.
Step 1: Choose the right plant. Transplanting root-bound plants is courting disaster, so look for plants that are not overgrown in their pots. Also, choose plants that haven't been water-stressed at the garden center. Buy your plants from centers that practice consistent watering. You don't want plants that are left wanting for water and then drenched to make up for having been neglected. "Dry then drown" watering will stunt any plant's growth.
Step 2: Measure the sun. At this altitude, plants must contend with intense sun, low humidity and the drying winds of spring. Plants that would grow in full sun in other parts of the country dry out and die in our demanding climate.
Areas with fewer than four hours of sun per day are perfect for shade-loving plants. Garden spaces with four to seven hours of sun, Most spaces with east- or west-facing exposures provide four to seven hours of sun and will allow just about anything to grow. Sun in excess of seven hours requires plants that tolerate hot sun during the growing season. Check the grower's tag or ask for help at you local garden center to be sure you have the correct plants for each space you'll be planting.
Step 3: Dig the right size hole. I like to use the "$5-plant-in-the-$10-hole" approach to successful planting. Digging the hole properly and spending a little extra money to amend the soil will reward you with a healthy, thriving plant. The bowl-shaped hole should be the same depth as the root ball of the plant, and three times the width. Plants don't need deep holes. They thrive when their roots can stretch out just under the surface of the soil in search of food and water. That's why a bowl-shaped hole will promote better root formation.
Step 4: Check for good drainage. Fill the newly dug hole with water. If all the water hasn't drained away within 12 hours, you've done nothing but dig a bathtub where your plant is sure to drown. If the hole doesn't drain adequately, dig a chimney-like hole in the main hole until you reach the next soil band, then check the drainage again. Contrary to popular belief, adding rocks to the bottom of the hole will not improve drainage.
Step 5: Make it better with compost. There are two types of soil in mountain gardens. One is hard clay, which does not drain well; the other is loose granite that water flows through as if it were flowing through sand. Good mulch can keep clay soil loose and aerated, and keep the water up around the root ball in loose granite.
Amend mountain soils with a good compost or mulch. Manure is too strong for new plantings; save that for when you're putting your soil on hold for the winter.
The volume of mulch per plant should be equal to the size of the root ball. That's how much mulch each plant needs blended with native soil. The average five-gallon plant will need about one cubic foot of mulch per plant. A one-gallon plant will use about 1/2 cubic foot. Before adding mulch to native soil be sure to remove all rocks larger than a golf ball. If your planting area has so many rocks that once you've removed them you don't have any native soil left, use a good potting soil and omit the mulch. A mulch-only planting medium will be too heavy for most plants, but potting soil on its own will add drainage and encourage healthy roots.
If you have mulch left over after planting use it as top dressing to insulate the roots from heat and cold. If you are working in a granite soil, you should buy an extra bag of mulch for top dressing: it keeps plants from using too much water.
Step 6: Don't bury the plant. The top of the root ball showing when you buy the plant should be showing at the top of the soil when planted in the ground. Too many problems are the results of plants, which have, literally, been buried to their deaths. Keep the plant's trunk out of the soil.
Step 7: Feed with a slow-release fertilizer. As many of you know, I like Start-N-Grow plant food. Just sprinkle it on top of the root ball. It's easy to use, it works well, and has a large margin for error that other foods don't have. A slow-release fertilizer will feed newly forming roots a little bit each time you water, promoting a strong, healthy root mass.
Step 8: Use rooting hormones. Of course, more roots mean a more vigorous plant for years to come. Rooting hormones cause plants to form many root hairs to grow into the surrounding soil. Root Stimulator is a liquid hormone that is added to water, which is then used to saturate the root ball before planting. In addition, this additive mixture should be used every two weeks for at least the first two months after planting.
I would like to hear your concerns, questions or thoughts about future topics for this column. You may submit them to me at Watters Garden Center, 1815 Iron Springs Road, Prescott, AZ 86305, or through my website at www.wattersonline.com. Just click on the 'Ask a Question' link, type in your contributions, and hit 'Submit'.
Until next week, I'll see you in the garden center.
Ken Lain, owner of Watters Garden Center in Prescott, is a certified nursery professional and master gardener who has gardened extensively throughout Yavapai