Any Questions? Trees

Q. We want to move some trees most of them are about 6 year old evergreens, do you have any advice please. Or can you advise of any contractors in the Cambridgeshire area.

A. You need to wait until they are dormant to have a good chance of success. This is towards the end of November or early December when all of the leaves have fallen off for the deciduous ones, and when all the leaves have fallen off the neighborhood trees for evergreens.

Dig around the trees and aim to bring up as much of the root ball as possible, you will probably have to cut through deep roots if the trees are very large. For a tree about 6 feet tall, you want to aim to have a root ball about 2 feet across if possible and about a foot deep. Then plant the tree in its new place immediately, stake it and water it and wait for it to wake up again in the spring. This is most effective with deciduous trees and if you have a good amount of root, stand an excellent chance of success. Evergreens are less easy to move and if are very large, success is rare.

If you can't wait until the tree is dormant, there's little chance of success as you will lose much of the root system at a time when the tree needs it all to replace water being lost by the leaves. It is not impossible, but unlikely to work well. You will need to water like mad when re-planted so that the root that does remain can get all the water possible.

As for contractors, I don't think any would want to take the job on before the winter dormancy period.

Q. I am considering buying a Robinia Frisia and they all seam to be grafted - is this ok or should you by a root tree? What are the pros and cons?

A. Plants are grafted to get the best of a good strong rootstock and quality top growth. Non-grafted trees will either have poor roots or be less attractive (but usually strong growing) above the ground. Go for a grafted tree, particularly a Robinia - non-grafted ones just don't have the same color.

Q. addendum. Thanks Paul for that info - very helpful. In fact the Robinia Frisia I have been looking at is apparently 'budded' not 'grafted' - I don't really know what the difference is - could you explain?

Research I have been doing has thrown up an interesting question about the rootstock Robinia Frisias are grafted to. Apparently the rootstock is R. Pseudoacacia which is a vigorous green-leaved tree with thorns. I have always understood this was the name given to the Golden leaved tree itself. If this is the case what is the name of the Golden leaved tree that is grafted to this rootstock?

I also understand they are very prone to suckering - if these were to grow it would be the green leaved variety - these are best cut off at the root if occur.

A. addendum. Robinia pseudoacacia is the species, Robinia pseudoacacia "Frisia" is a variety of that species (horticulturalists are not always very precise about taxonomy). Budding is a type of grafting where a single growing bud rather than twig or larger piece is grafted - different techniques suit different plants. I've never had any problems with this tree suckering, as you say cut them off at the root if any suckers emerge.

Q. Can you recommend a small (preferably not more than 10ft) tree with all-season (or three at least!) interest for the center of a small front garden lawn? It gets some morning sun and is slightly exposed to N and E winds.

A. There aren't many trees that will only grow to 10ft and those that do tend to be very slow growing so would be much smaller for many years.

I suggest that you go for a smallish tree and trim it to size if it starts getting too large, which won't happen for several years anyhow. I'd suggest the following;

Malus toringo ssp. sargentii. This is a crab apple and won't get much beyond about 12ft. Crab apples are good because you get spring blossom, summer foliage and fruit that continues through to autumn when the foliage turns as well.

Other crab apples and flowering cherries could be used though will grow beyond 10ft, taking usually over 10 years to do so, so it depends how adverse you are to removing it once it gets too big. Cercediphyllum japonicum, the katsura tree also fits into this category, about 15 years before it gets beyond your required height.

If height is all important, you could go for a weeping tree such as birch Betula pendula "Youngii" or cherry Prunus "Cheal's weeping" these are grafted at the nursery and spread wide with time but put on little height above the original graft.

A third option would be to go for a large shrub that can be trained as a tree, shrubs respond better to pruning to control height than trees. Euonymus lamarckii (shadbush), Euonymus europeus (spindle tree), Rhus typhina (stags horn sumarch) or several types of Cotoneaster can be trained as small trees.

Q. I found your site through a search for Betula jacquemontii. I have a question that has so far gone unanswered.

I planted 3 birch trees of this variety three years ago. Of the three, one looks considerable healthier and is growing larger than the other two. The curious part is that while they all appear to be the same type of tree, the larger of the three does not have the hanging "pods" that are on the others. My garden book says that all Betula have this characteristic. Any ideas?

A. My first thought is that your third aberrant tree is not what it claims to be - it isn't a Betula jacquemontii. The second possibility is that it is a "sport" of jacquemontii, Betula utilis jacquemontii is quite a variable group with several named cultivars within it and the ability to occasionally throw up unusual forms, which you may have. The fact that it doesn't have "pods" (actually male catkins or flowers) may be a question of age - it might have them later - or a characteristic of that particular tree - if it's not putting energy into catkin formation, it's got more available for growth.

Q. I recently bought two, Malus Red Jade weeping crab apple trees. They had a general plant description label, which said they would grow to 10ft by 10ft, however they also had a small sticker on the labels which said they were M27 dwarf root stock. I assumed all Malus Red Jades had this root stock as they are small trees. However I have since found out that they do not. In which case, how big will the trees I purchased grow to?

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 fertilizer and then a good mulch of manure or compost very year to get the best from them.

Q. Can you recommend a fast growing tree that would be good for climbing, that is for children to climb?

A. I'd go for an Acer, maple, of some type. They have smooth bark and are pleasant to touch and are fast growing. Usefulness as a climbing tree is more a case of being able to let it develop with branches low down rather than a high clear trunk which is how many trees are pruned in their early years.

It's difficult to recommend particular varieties as they vary so much in size, many have good autumn foliage color 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 favorable position.

Q. I have recently planted a Salix Caprea 'Kilmarnock' willow. I kept it well watered while it was still potted and it looked very healthy with flowers and green leaves when it was planted. I gave it a good watering when planted but then nothing all week as I was away. However, we did have quite a lot of rain recently. Unfortunately, the leaves are dry and curling and it looks very poorly in general. I have given it a good watering this weekend but it still looks poorly. Can you suggest what might be wrong and what I can do to help?

A. It's difficult to say without seeing it and the conditions that it is growing in. Many plants take a "knock back" when planted particularly if they are large and planted during the peak growing season.

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?

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