The scant rainfall and torrid weather has taken a toll on a number of my landscape plants. Because I value potable water, I prioritize its use. Edibles and newly planted shrubs and trees, which are highly vulnerable to drought stress, earn the right to receive water from my spigot. When plants become established, meaning that they’ve regenerated enough roots to sustain themselves without supplemental irrigation, they’re watered only when the need arises.
I follow this rule regarding tree establishment: for every inch of trunk caliper (trunk diameter measured six inches above the ground), it takes at least 6 months before a tree becomes established. During the establishment period, I apply 2 to 3 gallons of water per inch trunk diameter (for example, 2 to 6 gallons for a 2-inch tree) over the root ball. After a few months of frequent irrigation, I water weekly until the plants are established.
After experiencing several dry summers that spanned more than a quarter century, I know that even established shrubs and trees may succumb to hot, dry summers, which means that you need to visit your landscape often and be on the lookout for the initial signs of water stress: curling or crinkling leaves, yellowing or off-colored, du
ll-looking leaves, and brown or scorched areas along the leaf margins. Obviously when you see azalea leaves that look like brown potato chips or Florida anise leaves that look like wilted leaf lettuce, the damage is already done. More severe signs of water stress include leaf drop and branch dieback. These aboveground signs are only a reflection of the unseen damage belowground, particularly to the fine, water- and mineral-absorbing roots.
Despite my hardline approach to avoid watering established plants—or at best, only when absolutely necessary, I did lose some treasured specimens this summer. Less than a week ago I cut down a seven-foot tall Atlantic white-cedar (Chamacyparis thyoides) that I planted in 2012 from a 3-gallon container. Atlantic white-cedar, native to swamps and low lying areas along the coast from Maine to Florida, was a gift from the horticulturists at Moore Farms Botanic Garden in Lake City. A photo of this conifer accompanied my July 24, 2015 post on bagworms. Sadly, I never appreciated its bright green needles and natural pyramidal habit until it turned completely brown.
While it was difficult to lose this treasured specimen and a few others, I am comforted by the gain in planting space. I have about 30 replacements that need a permanent home. In a 20-square foot area beneath a small trio of northern red, Shumard, and overcup oaks, I have a variety of potted species and cultivars that I started from seed, rooted from cuttings, or received as passalong plants. I can only hope they’ll be amendable to my tough love approach to watering.
One tree that has survived for the past four years without any supplemental irrigation is an Italian Stone pine (Pinus pinea). I purchased it in a one-gallon decorative pot right after the Christmas holiday season. This Colorado blue spruce lookalike was on the discounted table surrounded by poinsettias and rosemaries sheared into miniature Christmas trees. After two bitterly c
old winters where temperatures dropped to 8 degrees F, this Mediterranean native is now three-and-a-half feet tall and thriving. It morphed from the cute, short-needled blue conifer into a shaggy-looking green-needled attention-getting specimen. Unlike other plants that have stopped blooming and growing, my Italian stone pine has 3 to 4 inch long expanding new shoots studded with short blue needles. I can’t wait for it to reach reproductive maturity so I can harvest its delectable pignolia or pine nuts for pesto.
Interestingly, I’ve read comments from a variety of “experts” on the internet who nearly dissuaded me from growing this Italian stone pine, which is widely planted in California and not expected to thrive east of the Mississippi, let alone in the southeast. Fortunately, Italian stone pines can’t read.
Copyright © 2016 Bob Polomski