Avocado’s in Spring
Question from Dave:
I have a very reliable and steady source of horse manure (1 quarter horse, 1 draft horse and 1 shetland pony) and an equally reliable source of pine needles. Using the old compost addage “something green and something brown” can I combine the two to create useful compost?
Thank you.
Answer from Pat:
You are very lucky to have a steady supply of horse and pony manure, but I would not mix pine needles with the manure if I were you. This actually won’t create the correct green/brown mix (Ie: carbonaceous mixed with nitrogenous.) Straight horse manure, alone, (unmixed with anything) is close to the correct green/brown ratio already. One can just pile it on the ground and let it age and once aged it can then be combined into garden soil. In some cases stable bedding is included with the manure. Usually there is enough liquid nitrogenous stuff (horse urine) included with the bedding to sufficiently rot it in time, but this would not apply to pine needles. The needles most likely wouldn’t rot.
Since we are having such good rains right now it’s an ideal time to spread the clean manure directly onto the ground over the roots of plants you want to mulch and gradually feed. Let it age right there and dig it in in spring prior to planting. By spreading it right on top of the ground all the goodness of the manure will be washed down into the ground by these rains and not wasted on the ground under the manure pile. It also causes less runoff this way since it is less concentrated and there is more ground to hold the nutrients in the soil instead of letting them wash away. Spread the manure on top of any ground that you want to improve with organics, such as a vegetable garden or flowerbed or over the roots of fruit trees or ornamentals. There is no reason to add the pine needles to the manure.
In my book I describe a compost made from alfalfa and manure layered together. This combination is different from one using pine needles, since it makes a great quick compost which is ready in about two months. (As soon as it cools down and you can no longer see what went into it, it is ready.) You can then use it as mulch all over the garden or dig it right into the ground. The reason this works so well and makes such a nutritious compost so quickly is because alfalfa is not carbonaceous but green or nitrogenous waste. In fact alfalfa is a major source of nitrogen when used alone as fertilizer and it rots quickly in the ground. Pine needles, by contrast, have no nitrogen in them. They are pure carbonaceous material, and they have a hard coating and texture that means they take much longer to disintegrate. (It should be noted, however, that the needles of certain pine trees, such as Aleppo Pines, are smaller and thinner and rot quicker than those of other pines such as Torrey pine trees, whose needles take months or even years to rot.) Composting pine needles is usually a long process and they are also highly acid. The best use for pine needles in a garden is as a long-lasting mulch covering the root zones of acid-loving plants, such as azaleas and camellias. Some people like to make a separate compost pile for pine needles, simply leaving them piled up until they age. Then they can even be used in soil mixes for acid loving plants. Other folks use them on garden paths in woodland areas under trees and shrubs, or at the backs of wide flower beds, but always on top of the ground. They make a very clean, good looking path cover.
Thank you for all the guidance provided. I switched over to mostly organic rose fertilizers and have seen a remarkable improvement in the roses. All 30 plants are at least 15 years old and a few have not looked so good in a decade. A fee new questions:
1. I’m concerned that I may have over-fed some of the avocados. I have 2 Jan Boyce types. Each in 15 gallon pots. They drain well but one has dropped it’s leaves and one is half way along in the same process but with brown tips on the leaves I buried some banana peel in the soil a few weeks back thinking that potassium might help. Good news is that both trees are pushing out new leaves. Suggestions?
2. I have a Reed avocado which had previously shown steady growth and looked good. It’s located on an area where the adjacent patio drains. The leaves have all turned yellow and are dropping. I’m thinking this tree has too much moisture. And I’ve noticed black flies hanging around. Are the black flies placing some larvae on the tree? Is it time for more green lacewings? This tree is pushing out new growth.
I can’t tell from the information you have given me if you overfed your avocado trees. Certainly banana peels would not be the cause of overfeeding. (See below for more.) But there is a problem with growing avocado’s in containers. 15-gallon pots are really not large enough containers for avocado’s; no container is large enough. These are big trees and need to be planted out in the ground.
Many years ago an avocado grower said this to me: “Never dig under an avocado tree or all the fruit will fall off.” I have found out since that this can apply to leaves also. I fear that by burying banana peels under your trees you broke this old law and inadvertently you dug under the leaf canopy of your trees. It will not kill the tree but damaging the roots of avocado’s can set them back for a whole season.
Seems silly, doesn’t it? But I’m afraid in this case you have to go to the trees and ask for an explanation of why they do this. Avocado’s have very sensitive roots and they depend on their surface roots that are right on the surface of the ground under the mulch all over the ground under the tree. I am speaking here of trees growing in the ground, not in containers.
Regarding the black flies hanging around your other tree I cannot say what those are. There are some beneficial wasps that look like flies with wings that stick out at right angles to their bodies. These are called Hover Flies and these often hover in the air looking for pests. I have often tried to see what they are going after but without success. Though I have sharp eyes, hover flies can see things I can’t see. Far from harming plants, these insects are looking for pests such as caterpillars and such which they parasitize.
The leaf drop on your Reed avocado might have come from overwatering but also it could be the result of sudden temperature changes and we have had those problems this spring. Growing avocado’s in containers subjects the roots to stresses such as might occur from the side of the container getting hot from sun and then getting cold at night. Hot sun can burn roots if they are wrapped around inside a black container and the container is in full sun. These roots belong in the ground with a layer of thick mulch above them to protect them from just such occurrences.