PEAR AND APPLE SCAB -- GOOSEBERRY SAWFLY -- CALCIFIED SEAWEED 1 -- BORDEAUX MIXTURE -- LIME WASH -- PLUMS -- PEACHES -- BITTER PIT -- COAL-SOOT SOLUTION: 2 June 2003
JK e-mails: Dear Mr Harris, I noticed in your book, which I am enjoying very much and am hoping to put into practice in my newly acquired allotment, that you invited people to contact you if they have any queries. Although my question isn't directly to do with moon gardening I wondered if you could tell me of any organic methods of dealing with pear scab and gooseberry sawfly. I'd also like to say I found your talk on moongardening very interesting, which you gave a few weeks ago to Egloskerry [a village in Cornwall] garden club. It's fascinating hearing about the old ways of gardening.
R J Harris replies: "Pear scab -- or apple scab: they are the same problem -- is all too common. When the attack occurs, early in the season, the developing young fruit becomes deformed and then, usually, falls to the ground. The very earliest Springtime sign shows up on the tree's leaves. They develop olive-coloured patches. The spores of the disease then spread from these patches to the individual fruits. If these manage to reach maturity, they show unsightly, large blotches and/or cracks and turn black inside. You cannot really eat the fruit in this state, and it is useless as a keeper. In storage, it rots. Needless to say, produce in any of these conditions must be removed from the garden as soon as it is seen and destroyed off site. Burning is best. At very least, it must be taken to where it can do no harm to the unaffected plants in the garden."
The fungus that is host to the disease overwinters just beneath the fruit tree's bark. It causes noticeable blisters and swellings and, in Spring, these release the spores that show up on the leaves.
The head gardener's counter measures are in three parts
1) during Winter, when the tree is leafless and dormant, the blistered bark is pruned from the tree and taken away to be destroyed. "Note," says Mr Harris, "the best time to do this is when the moon is at the end of its fourth quarter. Then, the plant's roots and sap are under least pressure from the water table, because the fourth-quarter moon's reduced gravitational pull on planet Earth has permitted the water table to fall to its lowest level. The overall benefit is least trauma to the tree as the surgery is carried out, and there is the least loss of sap"
2) in early Spring, before either leaves or blossom appear, spray the tree thoroughly with Bordeaux Mixture, following the maker's instructions, or with a garden lime solution. "Take one part of garden lime and thirty parts of water," explains Mr Harris. "Thoroughly mix the lime to a thick paste with as little as possible of the water, then add the remaining water in stages, mixing as you go. The result should pass through the pressure sprayer without difficulty"
3) the spraying is repeated just after the blossom has disappeared and the fruitlets have been formed, and again three weeks or so after that, if the signs of scab re-appear.
"Page 109 in the manual is worth a read," adds Mr Harris. "At the top, lefthand side there is a reference to calcified seaweed [see link at the foot of the page. Ed] and how good it is for the development of stone fruit such as plums and peaches. It also helps to deter pear and apple scab. Apply it to the ground around the trunk of the tree when Spring arrives and before the leaves appear. The best time for this is at the beginning of the moon's third quarter. From that moment on you have the benefit of about two weeks -- or two moon quarters -- of diminishing gravitational pull by the dying moon allowing the water table to fall back and, as a consequence, reducing the pressure upon the top soil. This renders the top soil increasingly receptive, causing the calcified seaweed -- and any other applied powder or liquid, come to that -- to be drawn into it much more thoroughly.
"The application rates are there, too, on page 109. And page 108 refers to feeding the fruit trees, which is relevant because a lot of the problems like scab and bitter pit (a peach problem, this) come about when the plants are under-nourished or have to struggle to get the nutrients that they must have if they are to be fully healthy."
Plants are no different from human beings in this respect, comments the head gardener.
"An ill-fed man or woman is likely to go down with whatever illness is prevalent more quickly than someone whose nutrient intake is as it should be, and who is fit and well as a result.
"It is the same with plants -- and it is surprising how many owners of apple and pear trees never think to feed them. All they see is a tree that looks big and strong, and they never doubt, season on season, but that that same tree endlessly manages to draw its feed from the ground that it is rooted in.
"That is not the case. Fruit trees -- especially the toy ones on dwarfing root stock -- must be fed the required trace elements and minerals in the required amounts at the required time each season. And that time, of course, is at the start of the moon's third quarter."
R J Harris applies the same reasoning to the problem of the gooseberry sawfly. This insect, too, can wreak more havoc on the underfed and, hence, sickly soft-fruit plant than on the fit and healthy one.
"It attacks the currant family as well as the gooseberry," notes the head gardener.
"It is the caterpillars that do the damage. You know them by their black heads and green and black spotted bodies with orange-yellow patches at both ends. Left unchecked, they strip the plant of its leaves. And that does the plant no good at all, which causes it to be a poor fruit bearer."
The caterpillars appear first in April and May, then in June, and then in August or September. They result from eggs laid by the sawfly on the undersides of the leaves. Given the opportunity, they feed until they are about 20mm in length, fall to the ground, protect themselves in cocoons and then, two or three weeks later, hatch into sawflies. These then take to their wings and return to the fruit bushes' leaves to lay their caterpillar-producing eggs, thus ensuring their place in the food chain of which the gardener, like it or not, is also a link. The August-to-September generation remains in the soil beneath the soft-fruit plant, spends Winter there, and emerges as winged insects when Spring arrives.
"Break the cycle," advises Mr Harris.
"You will know that the pest has arrived when you notice the small, round holes left by their feeding.
"Immediately, for you cannot act too quickly, remove each affected leaf and the caterpills sticking to it and dispose of both well off site.
"Continue doing this right through the season.
"At the end of the season, after the leaves have dropped and the plant is bare, remove from around the plant all of the fallen leaves and all of the mulch material that was placed there at the start of the season in aid of managing the plant correctly. The manual explains all about fruit-bush management, which is made up of a number of essential activities. Get the dead leaves and the redundant mulch well off site, for you can be sure that they are providing winter lodgings for the last of the season's sawfly caterpills.
"Then, make up Bordeaux Mixture according to its maker's instructions and use it to saturate the cleaned ground. Be liberal with it. The top soil must be well and truly soaked, and at least a couple of times as Winter turns into Spring. Do it again just before putting down the Springtime feed -- a dressing of the calcified seaweed, to rectify any trace-element deficiency, is a good idea -- and before putting down the Springtime mulch with fully-composted farmyard manure, as explained in the manual's instruction on soft-fruit-bush development and maintenance.
"But before this, during Winter, when there are no leaves and no blossom -- which is important, go to work with the pressure sprayer and give the dormant bush a thorough dousing with the Bordeaux Mixture.
"Do this a couple of times whilst the plant is still dormant."
The extremely bad infestation may require more than a single season's treatment.
"The key to success is vigilance," says Mr Harris. "From the very start of each season, from when the first leaves appear, examine the fruit bush closely. No drilled holes means no caterpillars, so you can rest easy -- whilst, of course, continuing to keep watch. The very first drilled holes means immediate plucking and then putting into operation the entire procedure right through the season."
The head gardener's preferred solution, whether for spraying or soil soaking, is based on coal soot, not Bordeaux Mixture.
"Unlike most people, I am lucky in having a supply of the stuff available to me," he says.
"I prepare it like the garden lime solution -- one part of soot to thirty parts of water and mixed really thoroughly so that the pressure sprayer can handle it easily."
The head gardener warns that the soot must be weathered and not fresh, as when taken from the chimney.
"This is coal soot that has been heaped in a corner of the garden and fully exposed to the elements for at least four months.
"It forms a crust on its top, but that does not matter.
"The weathering de-fuses or de-activates it, and makes it more ready to be mixed first into a paste and then into a sprayable liquid."
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