Q. I have a 30ft holly tree in my back garden it flowers but has never had berries. About half of the leaves do not have spikes on them, and are yellow. The tree is riddled with leaf miner It is dropping about 100 leaves everyday I have been picking them up every day for about a year and have seen no improvement. Also the trunk of the tree is covered with a green algae like residue.

The tree is beautiful and I would really like to help it back to health but I feel it might be to late.

A. Taking your points in order:

In all probability, your holly tree is a male, only females have berries, hollies are one of the relatively few plants that have males and females. If you want berries, I'm afraid you'll have to get some female plants which will be pollinated in order to set berries by your male plant.

Lack of spikes in itself is nothing to worry about, this is a factor of the variety of holly and also possibly a characteristic of that particular tree.

Yellowing leaves and so many dropping might be something to worry about though. All evergreen trees do drop leaves almost continuously as they are replaced. As it's been going on for a year it may just be that there's so many as the tree is large. On the other hand, is it getting noticeably more thread bear? It should be able to maintain an equilibrium of fallen leaves with newly sprouted leaves.

Hollies are susceptible to attack by leaf miner. If the infestation is heavy you can spray it with a systemic insecticide, but this will be a fairly large job and require a sprayer able to deliver large quantities and broadly - a hand sprayer will either not do the job or will build your forearms up so you could crush a billiard ball. Spray as soon as possible and repeat in a month or so, maybe again a month after that. If you want to be organic about it, you could crush the leaf miners in the leaf with your thumb nail, though I guess this is pretty impractical with the size of the tree. Is it stressed in any way that might make it more likely to come under heavy attack?

The algae is nothing to worry about, brush it off with water and a stiff scrubbing brush if you find it unsightly, though it will come back.

It will also help to feed the tree if it's under attack, I'd use blood fish and bone meal, or bone meal, you could use inorganic gromore or something similar. Depending on what's under the tree, spread the fertiliser in a circle about 6 feet radius around the trunk, hoe into the soil and water in liberally.

A. I have never actually come across this tree grafted onto this root stock, so I can't really give you other than a generic answer. M27 is a very dwarfing root stock and you wouldn't usually expect a tree on such a root stock to exceed much over 6ft in height. As Red Jade is a weeping tree and so will not grow upwards, then I wouldn't expect it to get any higher than this.

Trees on M27 usually need good growing conditions to do well, they don't perform on poor soils as the roots are unable to go and seek out extra nutrients. I'd give them a good start with manure or compost in the planting hole and some blood, fish and bone fertiliser and then a good mulch of manure or compost very year to get the best from them.

It's difficult to recommend particular varieties as they vary so much in size, many have good autumn foliage colour too, so I'd go for one with this as an added feature.

Native British trees such as oak, ash and beech are good too, it's the early training and development of spreading branches low down that is more important than the variety.

Ultimately it's probably time that is the most important aspect. My youngest son is 10 now and if I planned ahead I might have a tree large enough for his children when they're about the same age. I don't know of anything that would grow fast enough in the UK to keep up with a child already born, maybe a Eucalyptus if it's in a favourable position.

Lack of water is a possibility, willows require large amounts of water and trees in general need looking after through their first season at least. It is possible that the damage was caused if there were a few dry windy days in a row with no rain, the limited root system may not have been able to cope with drying out soil. Were the roots damaged when you planted it?

Q.  I Was left a plum tree by my father which I planted 4 years ago I don't know a lot about plum trees but this year I had fruit grow which weren't very big or looked edible but the tree has grown to about 12 foot and has a thin trunk which bends over could you tell me if it needs pruning or trimming as I haven't got a clue and it is important to me that I look after it as best as I can your help would be greatly appreciated.

What variety of plum is it? Could it be a damson tree? they're small and used for cooking usually. Sounds odd that it's bending over.

What to do? Clear the ground around the base at least 2 feet in radius and apply a thick mulch of garden compost. If it needs supporting, then 3 short stakes with long ties each about 2 feet from the trunk and tied quite high up would work or a single 6 foot tall post next to the trunk, but this might damage the roots if you dig or hammer it in.

To be honest a tree that is that condition and is 12 foot tall doesn't have a lot of chance to become normal. It's either in the wrong place or it wasn't staked correctly when it was developing. I assume it has a sentimental significance, so it's worth trying what I've suggested, but if it didn't I be considering replacing or risking moving it to a more advantageous position - a lot of work and no guarantee of success.

Postscript:

I thought I should give you some feed back on the advice you gave me last year.

As advised by you, I cleared the grass for about 2 feet from the trunk and gave it a good dose of potash last summer. In the autumn I gave it a good amount of mulch ( rotted compost heap material) and followed up with another potash feed in the spring. The results have been tremendous with a big crop this year, although the size of the plums has been small (probably due to the real lack of rain here).

So all in all a very satisfactory result. Many thanks for the advice.

A.   There's a chemical you can get to kill stumps, based on ammonium cholate, comes in various brand names that will be the least effort way. Cut it down to leave a short stump a few inches high and then apply the chemical.

You can get rid manually by cutting it down and then removing any new shoots on a regular basis at least every month rather than leaving it.

There is no no-effort way of doing it unless you pay some-one else or poison the whole thing when you have one large dead tree that will slowly rot and drop branches while looking very unsightly.

Q.  I have a Malus, not sure which, but a few years ago it started to lose leaves early due to very long hot summer we thought. It came back the next year but appears to have got worse in the last two. We have had it pollarded but have now noticed that the bark is peeling off in places and woodlice are eating away. Has it had it or is their anything we can do. It is a very old tree at least 40 years old apparently.

A.  Some Malus varieties are short-lived trees 30-40 years, so it's likely that yours is on its way out before you tried to take action. Pollarding it wouldn't have really helped such an old tree and it seems like this was the last straw. Time to cut your losses (and the tree) and replace it.

There are a number of pesticide resistant strains these days. The best bet is to keep a careful eye on your tree and spray at the absolute first sign of infestation. The pesky little critters have a very high rate of reproduction and can soon reach high densities.

Malathion, or similar insecticides work but must be sprayed at 3 - 5 day intervals. The real secret to beating these as many other pests is to get them quickly and before they establish. In the summer I usually keep a small spray of insecticide permanently made up to blast these and other pests such as aphids with as soon as I see them.

You need to make sure that the spray actually reaches them all. I know it sounds obvious, but they hide under leaves and make fine webs over themselves that even fine spray drops don't always pass through.

There is a predatory mite that you can buy as a means of biological pest control that has very good results if used at the right time, and they can't get resistant to that!

Q. I have a 10 year old live oak that is approximately 7 feet from our concrete patio and about 20 feet from our two story home. It has a surface root that extends about 5 feet from the base of the tree and is heading for our home. May I remove the root to eliminate any danger to the foundation of the home? I cut a smaller root 2 years ago an it has shown no apparent damage but this root is larger.

A. May I remove the root to eliminate any danger to the foundation of the home?

I'd say you should definitely do this! There are many variables involved, climate, soil type, annual variations etc. But that tree is too close to your house. It will grow to dwarf the house eventually. The main danger is probably not because of the roots damaging the foundations, but from the tree drying out and shrinking the soil during a dry summer and so causing subsidence. Oaks get mighty big and can lose huge amounts of water in the summer when they are mature. It may not be an immediate danger, but as a rule of thumb, when it starts getting as tall as it is far away from your house, you need to start thinking about felling it. You may get away with it and it cause no problems at all, but the risk is there. If you cut that root, the tree will just need to replace it and it may do so deeper where you can't see it.

My question is when is the best time to prune it, and how? Should I cut back some of the stunted growth that remains, should I cut back the new growth as well, and try and re-shape it?

The bad news is that Rowans don't really like being pruned at all and badly misshapen ones are often best replaced. Now is the time to do it though (winter) before the buds break for spring. I think your best approach is to try to re-shape it irrespective of strong or weak growth. Why is it lopsided? Is one side in a lot of shade? Can you do anything to remedy the cause - if any is apparent - of the lopsidedness? The usual advice for pruning is to prune strong growth lightly and weak growth hard. Try not to remove more than 1/3 of any branch, but you can go to 1/2 in some places. It's difficult to be precise without seeing the tree itself.

Q. I have a 25 year old plum tree in my yard that has never flowered or fruited. I have heard that pruning all the leafing branches off the tree will allow the tree to restart production. Would you recommend this? Is there any less severe action you can suggest? It is a pretty landscape tree, so I would hate to kill it.