Thompson & Morgan Facebook Q&A Session 18th May 2012 - Your horticultural questions answered.

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Name: Julie Atkinson

Question: Hi, I have a question for Sue please. I recently bought a spiral laurus nobilis tree - are the leaves safe to use in cooking?

Answer: Hi Julie. Yes you can use them fresh, or dry them for use later. Just remember to give them a wash first.

Name: Wendy Stanbury

Question: My apricot tree that I bought from T&M; last year hasn't done anything this year apart from ooze sap, is it dead? No leaves, not blossom, just sap.

Answer: Hi Wendy. It sounds as though it could be one of two problems. Apricots are particularly prone to ‘gumming’ in which the stems exude beads of sticky sap. This is usually caused by a lack of nutrients, or poor soil conditions, and often the tree appears to lack vigour. Gumming can usually be rectified by feeding the tree and improving the soil. Keep the tree well watered, particularly in hot, dry periods and apply a mulch around the base of the plant to help conserve moisture in the soil.

However, if the tree shows signs of die back then the problem may be bacterial canker, which is more serious. Scrape a few bits of bark back on some twigs and branches with your thumbnail to see whether they are still alive. If they are brown underneath the bark then these parts of the branches have died. If they are green, then these twigs are still alive. Check for sunken areas of dead bark where the sap is oozing.

Bacterial canker particularly affects stone fruit trees. The bacteria enters wounds caused by pruning, natural causes and even leaf scars that occur during leaf fall in autumn. This normally happens during wet and windy weather in autumn and spring.

Infection can be controlled by pruning during the summer months only when the wounds will heal quickly. Apricot trees should be sprayed in autumn to help control peach leaf curl, and this will also help to prevent bacterial canker. However, young trees that have become infected are usually best replaced though.

Name: Be Jal

Question: Is it ok to cut my Japanese maple back to old wood at this time of year? Now that the leaves have opened it is casting too much shade onto the plants below. Thank you

Answer: Hi Be Jal. Normally Japanese Maples need only very minimal pruning and this should be done in winter during their dormancy as they have a tendency to bleed sap whilst in active growth. If you are only removing occasional twigs then you could probably get away with it, but it sounds as though you are planning on removing a larger branch, and this would be best done in winter. If your other plants are being shaded out then it may be worth finding a new position in the garden for them (particularly if they are annuals or perennials) rather than pruning your maple to make space.

Name: Elaine Randalln

Question: Ideas please, I'm a spinally disabled 50+ woman, I have a quarter circle paved area, (coloured blocks) in a corner of my garden, at the moment it's just got ornamental ( mostly glazed blue)pots on it but it looks boring, I want to snazz it up a bit, and kind of pot on pot waterfall planting? Any ideas? I'll try to put a photo of the area on here later.

Answer: Hello Elaine. Why not treat yourself to a 3 Tiered Planter and fill it with colourful trailing annuals. Lobelia, Petunias and Begonias are all ideal for providing cascades of colour.

Name: Simon Gibbins

Question: I have almost completed building a poly tunnel, twenty feet long, for veg. But my wife would like a small patch to grow flowers. She has never grown anything before, but would like a challenge. Can you suggest anything colourful/a little quirky perhaps/ not your every day flower. Thanks

Answer: Hi Simon. This is difficult question to answer as it really depends on what your wife wants to achieve. Does she want to grow flowers for cutting, or maybe an edible flower garden to complement your vegetables? Both would still look very attractive but would give an unusual theme to her patch. How about a wildlife garden close to the door of your polytunnel to encourage pollinating insects inside to help pollinate your crops? Personally I think that part of the fun of gardening is planning what you want to grow. Why not let her have a browse around our website and see what takes her fancy!

Name: Lucy Garden

Question: An over-enthusiastic helper cut off a deciduous azalea in its prime - right through the main stem. All that survives is a small weedy offshoot with a couple of tiny leaves, growing from a bare twig about 18 ins high. Will it regenerate?

Answer: Oh dear Lucy. I bet you were cross!! Unfortunately azaeleas are quite difficult to regenerate from such hard pruning because new growth is not easily produced from older, thicker stems. I’m afraid that you may well lose this plant - but give it chance over the summer to prove me wrong! If you see no growth by autumn, then accept defeat and buy a new one.

Name: Alejandro Canepuccia

Question: Hi, I purchased seeds of Lathyrus odoratus and L. latifolius. I grew these seeds at our autumn (Southern Hemisphere). The L. odoratus grew vigorously, but the tips of young leaves of the L. latifolius has quickly dried (see photo). Currently, the weather in my city is cold and wet. I water the plants once a week. What could be causing of the dried tips? I'm very grateful for any suggestions that you can give me to maintain my plants healthy .

Answer: Hello Alejandro. The damage in the picture looks very much as though the plant is suffering from a lack of humidity. Are you growing these plants indoors? If so, then they may be suffering from dry air caused by central heating. Make sure that the plants are not sitting close to draughts and radiators, and try misting them daily as well.

I also notice that the damaged leaves appear to have been cut (presumably where you have tried to remove the damaged parts of the leaves). It’s best to avoid doing this as the leaf will just continue to die back even further in response to being cut. I know that it may look unsightly but it is better to solve the problem rather than remove the damage. I hope that gives you a few suggestions but feel free to send more information if you need further advice.

Name: Farooqui Yawar

Question: I purchased Rudbekia cherry brandy , Butterfly bush mixed , Lysimachia atropurpurea , Geranium Marverick Mixed , Papaver bacteatum , Geranium Wallichianum 'buxton's blue' , Lobelia string of pearls ,Godetia amoeria ' rembrant ' ,Primula polyantha gold laced ,Nemesia caerulea , , Delphinium hybrida ' pagan purples ' , Heliopsis scabra giant double hybrids . Please tell me ' WHEN ' to sow as per Indian climate. I am living in north India, Uttar Pradesh. We sow Gazania, aster , phlox , ice plants , dahlia , sweet William , sweet sultan in Oct and get flowers in Feb. and march. All are treated as an annual.

Answer: Hi Farooqui. You have bought a good mix of annuals and perennials which require similar temperatures to the Gazania, Ice Plants etc that you already grow. You can certainly sow your seeds in autumn and over winter them for spring flowers (as you would with your gazanias and iceplants etc.). The butterfly bush can be sown around the same time; however I think that you would need to keep it well watered and shaded in the first year or two to help it adapt to your hot summers.

Name: Gaz RocknRolla

Question: Fruit Tree Problems: I am currently growing 10 fruit trees in large pots (95litre per pot x 10). I have apples to apricots, figs to hazelnuts, peaches to pears and a nectarine etc. My problem with 3 out of the 10 trees that they have not leaved, bud or even flowered yet and concern is they might have died of over watering (rain) which would be a shame. The trees in question are a Conference Pear, Red Haven Peach and the Harko Nectarine. So what can I do about the problems I am having. Please help?

Answer: Hi Gaz. First of all, you need to establish whether they are alive or not. Scrape a small piece of bark on the stem with your thumbnail to see whether it is green underneath. If so, then they are still alive and you may stand some hope of saving them.

You mention that they may have become too wet over the winter. Containerised plants are much more prone to extremes of weather when grown in pots than if they were planted in open ground. But there are a few things that you can do to help prevent this. Waterlogging usually becomes an issue where the pot has few drainage holes, or if it is sat directly on the ground (which can block the drainage holes). Try raising the container on pot feet (particularly during the winter months) to allow excess water to flow freely from the container.

It’s also worth reviewing what type of soil you have planted your trees in. It is a common mistake to use a multipurpose compost for planting trees and shrubs in containers where they will remain long term. Multipurpose compost contains a lot of organic matter but tends to lose structure quickly and can become easily compacted and poorly drained. It is much better to invest in a soil based compost such as John Innes No.3 which is specially designed for this purpose and will drain much better. Also consider whether you may have over-potted them. If the container is too large then it will hold a larger quantity of water in the soil which your newly planted tree is unable to cope with, particularly during winter while it is still dormant.

If your trees are still alive then I would suggest that you repot them and try to nurse them back to health. Move them to a sheltered position away from strong winds and sheltered from strong direct sunlight. Keep a close eye on watering and only water when the compost begins to dry out a little. I hope that helps, Gaz.

Name: Cheryl Maclaren

Question: Hi! I have a really small garden and no greenhouse (sadly) and have been growing broad beans this year. They are coming along well but the trough I've been growing them in (about a 1.5 meters wide by 0.5 meter deep) is starting to get a bit crowded (there are 8 plants in the trough). How much space do they need? They are thriving well but don't want to restrict their bean producing potential if I should be thinning some of them out. Any advice would be appreciated. Thanks X

Answer: Hello Cheryl. Broad beans should normally be spaced at a distance of about 23cm (9”) apart so your plants are a little on the close side but it shouldn’t affect them too much. I would leave this crop as they are, but next time just sow 6 or 7 plant instead of 8. Don’t forget to pinch out the growing tips after the first flowers have set pods, to deter blackfly and encourage further pods to set.