A few weeks ago I was struck by yellow foliage on a number of my young pines. After thinking about it for a moment, I came to the conclusion that I hadn’t been fertilizing enough. Black pines in development require a lot of fertilizer. If they don’t receive enough food they can quickly turn yellow. Fortunately the solution is simple – feed more! I began feeding my trees more frequently – about twice a week with fish emulsion – and applied chelated iron to help the trees green up. As you can see below, some of the trees greened up more quickly than others.
The tree on the left is still a bit yellow – both trees receive full sun
Feeding this time of year is important for all varieties as it’s the last chance trees get to increase their strength before winter. This is especially important for trees that we may not feed as heavily in the spring like white pines or deciduous varieties.
Depending on the weather, some varieties will continue to grow into December where I live. Others are already slowing down. I’ll continue to feed the trees that are active and slow the feeding schedule as the weather cools.
Every year I experiment a bit with fertilizer and every year I seem to keep returning to my standard duo – cottonseed meal and fish emulsion. Although they’ve worked well for my trees, I’d like to try a more balanced mix this year. The fish emulsion I use is rated 4-1-1, the cottonseed meal, 6-2-1 – neither providing much phosphoric acid or potash. Boon has used Phyta-Grow brand fertilizer from California Organic Fertilizers, Inc. for years so I thought I’d give it a try this year. We’re using a 50-50 mix of the Pre-Plant PlusTM (7-5-7) and the Veggie MixTM (8-5-0.5) for a combined 7.5-5-3.75.
Equal parts Pre-Plant PlusTM and Veggie MixTM
As I’ve done with the cottonseed meal in the past, I filled tea bags with the fertilizer and held the bags in place with toothpicks.
Toothpicks and tea bags
Filling a bag
Folding it shut
My primary obstacle to using more balanced fertilizers in the past has been the critters that run off with the bags in the night. They tend to leave cottonseed meal-filled bags alone, but whenever I place anything more interesting inside, they don’t seem to last more than a few days before vanishing. Just a week after trying this new mix, the first few bags have already been torn up, but I’ll wait and see how the rest of the lot fares before switching back to cottonseed meal alone.
Last month I began using tea bags filled with fertilizer to feed my bonsai. Unfortunately, it only took a few days for me to realize that this technique didn’t work well as implemented. The bags started disappearing immediately. Critters tore through some of the bags and carried others away completely, leaving behind the toothpicks that were meant to keep the bags in place. Somehow they removed all of the bags from my best trees and only a few of the bags on the developing trees – I won’t even try to solve that one. Instead, I’ll go back to my time-tested fertilizer method – clumps of cottonseed meal and fish emulsion.
Tea bags intact on a pine forest
Tea bags on an exposed root pine
Cottonseed meal on a pine
More cottonseed meal
I usually start feeding my trees at some point between late January and mid March depending on the weather and the variety. If I’ve repotted a tree, I wait about 4 weeks before feeding it. I start by placing one or two clumps of cottonseed meal and add additional clumps every 1-3 weeks later until the majority of the pot is filled with fertilizer.
Cottonseed meal feeding a recently separated cryptomeria
I supplement the cottonseed meal with fish emulsion (see “Bonsai Fertilizer” for details). Fish emulsion is a great, if stinky, fertilizer that I’m comfortable using on all bonsai varieties. I usually apply fish emulsion weekly, though I might apply it more or less frequently at various times depending on the season, the weather and the variety.
Ebihara fed his trees with diluted liquid fertilizer every three days (I don’t know what type of fertilizer he used). Others primarily rely on dry fertilizer that releases food whenever the trees are watered. I haven’t noticed big differences between liquid, dry, or other categories of fertilizer, but I do find that consistent application leads to the best results. And the best results, of course, depend on the goal of the fertilizing program. If I’m trying to increase the size of the trunk, I fertilize a lot. If I’m trying to ramify delicate branches on deciduous varieties, I fertilize very lightly and only after new leaves have hardened off.
As for the tea bags, I haven’t completely given up. I may yet try chili powder or some other caustic agent that’s harmful to vermin but safe for trees. And if I can get this right, I will celebrate and then post the results.
A simple and tidy way to apply bonsai fertilizer? Tea bags.
I’ve seen a number of folks use tea bags to hold fertilizer, but I hadn’t tried the technique until this year. I typically pour mounds of cottonseed meal on the surface of the soil, but much of the fertilizer washes away, and the rest seems to seep into the soil and slow down drainage. Liquid fertilizer like fish emulsion is great – see “Bonsai Fertilizer” for details – but it requires following a schedule to make sure trees get enough food. Using tea bags keeps the fertilizer in place and is easy to clean up at the end of the season.
The technique is simple. Fill up a tea bag with your preferred fertilizer and pin it in place with a toothpick.
Tea bag with cottonseed meal (6-2-1)
All wrapped up
Tea bags can also help keep dango in place. I picked up a tin years ago, but don’t use it much as critters usually run off with the stuff the first night. I’m hoping the bags will curb this behavior.
Tin of dango
Two dango pellets
I sat around for an hour last weekend wrapping packets of dango and cottonseed meal. I threw them in a bucket and then walked around placing them on my trees.
Dango – ready to go
I used wooden toothpicks to hold the bags in place. Bamboo toothpicks are a great alternative as they don’t break down so fast.
Pinned in place
Pine with dango
I’m hoping the local critters don’t think of the bags as to-go containers. If they do, I don’t know what I’ll try next.