A Primer On Palm Planting
by Matt Bradford (MattyB 14:39, 13 June 2007 (PDT))
Upon hearing the story of one of my wife's co-workers who recently lost several newly planted, very big and expensive King Palms (A. cunninghamiana) after they rotted in clay soil with bad drainage, I decided to share my experience on improving soil quality, drainage, and planting techniques. I've only been growing palms for about 4 years so by no means am I an expert, but I have been very successful combining others advice and my own hard work to improve poor drainage in my garden (due to hard packed soil and clay). The first mistake that my wife's friend made was digging an extremely deep but not wide hole, then backfilling it with the same clay-impacted dirt. She essentially created a sump for all of the run-off from the surrounding ground to collect in. The roots just sat in stagnant water and the palms subsequently rotted. I made this same mistake when planting a few of my first King Palms and, although most didn't rot and die, they just sat there and their growth just seemed to bog down. Yes, digging a large hole is good, but you want to dig it wide, with the deepest parts around the edges, allowing the newly planted palm to sit up on a shelf in the center of the hole. You can even go a step further and dig smaller, deeper holes around the edges, and/or dig a trench leading excess water down and away from the plant. You should then fill these holes and trench with gravel, sand, or rocks.
Now you're ready to get the plant out of the pot and set it in the hole. This can be tricky though, because the potting soil is usually light and loose. I've had many botched plantings that end up with me frantically holding together a crumbling ball of soil and yelling, "Honey! Can you come out here and help me?" I've also read that some palms, like Brahea (B. armata) and Bismarckia (B. nobilis), don't like their roots being disturbed, so it would be best if you had a plan of attack if your going to be handling a root ball larger than you can hold in your hands. I recommend the following: Carefully cut around the bottom of the pot, trying not to cut through any roots (but do not remove the bottom yet). Cut the pot vertically and hold the pot together with bungee chords, if needed. Pick the pot up from the bottom and set it in it's final resting place...where it will live a long happy life, of course.
Lift the plant up and remove the container's bottom. Now you can begin your backfill, and as the dirt rises you can remove the bungee chords and pull the pot away. But not so fast! Don't just refill the hole with that old clay dirt, you'll have wasted all of your hard work. Mix about equal parts of your native soil, coarse sand, and compost (don't skip on the compost or you'll just be making mortar).
You can often get as much compost as you want for free at your local landfill. Now backfill the hole with your newly ammended soil. Finally comes the single most beneficial thing I've done for my garden...worms! Jessie Bergman at Jungle Music (palm nursery in CA) suggested this to me, and the worms have continued to improve my soil quality and drainage long after planting. In fact, the clay soil around one of my original Kings that I mentioned above, opened up and started draining within 2 weeks of adding worms and compost (worm food) to the surface only. You can buy a 10 Lb bag of worms at nurseries like Walter Andersen's for about $15.00. That's it! Have fun with it, experiment for yourself, and you'll soon have your preferred methods for making your garden a place for palms to thrive.