Can wood ash diluted with water at a ratio of 1 to 10 be sprayed on orchid leaves?
Wood ash is a natural high-potassium fertilizer. It is used very frequently in agricultural production and plays an equally pivotal role in flower cultivation. Used properly, wood ash not only keeps the roots of flowers and plants healthy, but also makes the stems strong, the leaves green and glossy, prevents pests and diseases, and prevents premature leaf aging and yellowing. So when growing orchids, you can use wood ash leachate as a foliar spray to supplement potassium and prevent pests and diseases. However, when using wood ash leachate on orchids, you need to pay attention to the following issues, otherwise it may have the opposite effect and affect the growth of the orchids.
1. Choose high-quality wood ash
Wood ash is the residue left after plants are burned. Many flower growers believe that the more thoroughly the plant is burned, the higher the quality of the wood ash. In fact, this is a mistaken idea. After a plant is completely burned, the ash turns grayish-white, and at this point the potassium content decreases, greatly reducing the fertilizer effect. Truly high-quality wood ash should be black, meaning the plant was not fully burned. So when choosing wood ash, try to choose the darker-colored kind and avoid the grayish-white kind.
Of course, the shade of the wood ash is also related to the type of plant. Some are very dark after burning, while others are a bit lighter after burning, so treat each case individually. When making wood ash at home, do not let the plants burn too thoroughly. When they are almost completely burned but not yet burned out, put out the fire. You can use rice straw, wheat straw and other easily combustible materials to make it. Try not to use hard wood, as it tends to burn incompletely and the solidified matter is too large, which is not conducive to dissolving and using.
2. Get the ratio right
When using wood ash leachate as a foliar fertilizer for orchids and other flowers, the ratio must be right. If the concentration is too low, it has little effect; if the concentration is too high, it may cause fertilizer burn. It is recommended to control the ratio of water to wood ash at 100:5-8, that is, dissolve 50 to 80 grams of wood ash in 1 kilogram of water (about two mineral water bottles). Some flower growers dissolve 100 grams of wood ash in 1 kilogram of water, which is also acceptable if not used particularly frequently, but for weak-growing orchids this ratio is a bit on the high side.
How much is 50 to 80 grams of wood ash? It is indeed hard to manage without a weighing tool at home. I usually just use two mineral water bottles of clear water and add a small handful of wood ash, and I have not seen any adverse symptoms from using it. If you have a weighing tool at home, it is best to be a bit more precise; if you really do not have one, just estimate roughly. In addition, when using wood ash leachate on well-growing orchids, the concentration can be slightly higher, and when using it on weak-growing orchids, the concentration can be slightly lower, so be flexible. If the flowers and plants have bugs and you want to use wood ash leachate to kill or prevent pests, the concentration should be a bit higher than when used as fertilizer, and the effect will be better.
3. Soaking time must be sufficient
Most of the nutrients in wood ash will dissolve into the water, but this takes time. It is recommended to soak the wood ash for 48 hours at best, and no less than 24 hours at minimum, otherwise the nutrients in the ash will not fully dissolve, which will affect the fertilizer effect. Some flower growers soak wood ash for only one or two hours before using it, and then wonder why it does not work.
4. The wood ash solution must be fully filtered
After soaking the wood ash for a period of time and feeling that the fertilizer effect has mostly dissolved, you cannot spray it directly on the flowers. It is best to filter it, remove the residue, and keep only the clear liquid before spraying. This has two benefits: one is that it will not leave water stains, spots and the like on the leaves of orchids or other flowers, which would affect their ornamental value; the other is that it is easy to spray and will not clog the nozzle of the spray bottle.
For flowers with high ornamental value in their leaves, such as orchids, clivia and spider plants, the wood ash leachate must be well filtered, otherwise it is very easy to leave spots. Some flowers have fuzzy leaves, such as herbaceous begonias and rhododendrons, and the wood ash leachate should also be filtered thoroughly before spraying. I usually use an old face mask and filter two or three times, making sure it is clear before use. It is a bit troublesome, but after use the flower leaves are very clean and the leaf color improves quickly.
5. Do not use the wood ash solution too frequently
For ordinary flowers, wood ash can be used at most once every 7 days, and for orchids and other flowers that do not need much fertilizer, wood ash can be used once every 15 days. Wood ash is good, but do not use it too frequently. During the peak growing season, using it once or twice a month is enough.
6. Wood ash must not be used together with nitrogen fertilizer
When using wood ash, note that it must not be used together with nitrogen fertilizer, as this will reduce the fertilizer effect. It also cannot be used together with acidic fertilizers, which will likewise reduce the fertilizer effect. So when using wood ash leachate, it is best to use it alone and not mix it with other chemicals or fertilizers.