Ask the Expert

Is it ok to cover the earth under ericaceous shrubs with Growise landscape mini bark as a weed suppressor?

Posted 04/11/2015 by Derek, Anglesey

Hi Derek, We recommend that a weed suppressive membrane is used to get maximum weed suppression with our bark products. This membrane will also minimise the contact between the bark and the soil. There is a small chance that the bark, as it degrades will alter the pH of the soil and a membrane will help minimise this.

We were gifted with one plum tree, two pear trees and two apple trees about six years ago (no idea of varieties); while we have had lots of plums (except this year when we had a very poor bounty), our pear trees have been a disaster with only one giving us fruit which was last year, and the apples are not good quality at all - small, few and cracked. We have made a bit of an attempt at pruning but we don't know what we are doing! Any advice on the non-production of fruit and tips on how to prune oldish trees?

Posted 05/10/2015 by Noelle, Co Tipperary

I cannot be sure what is wrong with your trees, but it sounds as if there may be multiple problems. Some varieties are not the best for our Irish climate. The lack of fruits may be because you have incompatible varieties, or that the flowers are getting damaged by frost, or that there are not enough pollinating insects about. All fruit trees need a sheltered and warm spot — especially pears and plums. And they all like good, fertile soil. Cracked apples might be due to apple scab, or to irregular watering. With older trees, in general you are aiming to remove old and tired wood, and to return the trees to an open shape, so that the air and light can get at them.

I have a space at the bottom of my garden which is under a tree so while it gets sun all afternoon, it is very shaded the rest of the day. The soil slopes down from under the tree so it's dry with good drainage. What plants would you recommend to sow in a spot like this?

Posted 05/10/2015 by Jacinta, Dublin

For a position like this, you can't beat cranesbills, also known as hardy geraniums. There is one kind, Geranium macrorrhizum, which is particulalry good for dry shade. There are several cultivars available, including ‘Bevan’s Variety’ (pink flowers), ‘White-Ness’ (pure white), ‘Album’ (white with pink buds) and ‘Ingwersen’s Variety’ (pale pink with rusty-red buds). It is semi evergreen, and it blooms for about 6 weeks in late-spring. The leaves are a beautiful shape and they have an interesting resinous scent.

Hi there, I planted mint in my garden a while back but now it’s sprouting up all over the place. I keep pulling it out but it’s taking over the garden, what can I do?

Posted 18/08/2015 by Phyllis, Dublin

Hello Phyllis, Mint is a sneaky plant, and it spreads all over the place by underground runners. So, I’m afraid that it’s a case of the horse having already bolted. The only way to get rid of it is to dig it up, or to treat it with weedkiller. In future, grow mint only in containers, or where you don’t mind it spreading. Mint is happy in shade, and is useful for colonising neglected patches.

Hi, I sowed rhubarb from seed a few years ago and it has grown very well except it is very green and bitter. The variety was called champagne and on the packet it looked extremely red which is what I like. Is there any way to make it redder? Thanks,

Posted 17/08/2015 by Terry, Carlow

Hello Terry, ‘Champagne’ rhubarb has very red stems, and good, deep flavour. As with all rhubarb, it should be grown in full sun, in very fertile soil, and with plenty of moisture. Seed-raised rhubarb is not always reliable, and it sounds as if you have been unlucky. Painful as it is, I think you might be best cutting your losses and seeking out some new rhubarb plants, either from a friend or from a retailer.

Is there a way of getting rid of bindweed?

Posted 21/07/2015 by Angela, Co Wicklow

Bindweed is one of the most persistent weeds, and if there were an easy, reliable way of getting rid of it, someone would be very rich today! In my experience, it is almost impossible to completely eradicate it, and you can hope only to control it. Here are a few methods that you can try. 1. Cover the whole area with carpet or other weed-suppressing material for at least a year, so that lack of light eventually kills off the roots. Be careful of shoots running out from the edges of the covering. 2. Carefully dig over the infested area, and remove the white roots. If you can then leave the area for a few months over the growing season, the roots you missed will resprout, and you can go at it again. 3. Spray off the entire area with weedkiller, leave for a few months, and spray off again when new growth has appeared and is growing strongly. If you use a weedkiller, wear protective gloves and eyewear, and follow the instructions on the packaging carefully. Note that bindweed wilts naturally in autumn, and there will be no regrowth until spring. Weedkillers work best in spring and summer when growth is strong. 4. If you cannot start with a clean bed, that is, if there are shrubs or perennials that cannot be moved, then you can spot-treat the bindweed. Stick bamboo canes into the ground so that the bindweed twines up them, and when there is good growth, brush on weedkiller, but be careful not to get it on the surrounding plants. You may need to do this over a period of two or three years. 5. Use any of the methods above, combined.

In the autumn, can I cut back hard my lavender plants - back to the woody branches?

Posted 20/07/2015 by Angela, Co Wicklow

Unfortunately lavender does not usually regenerate from woody branches. If the plants have become old and straggly, it is best to replace them with new ones in spring. Pruning is best undertaken in late summer, when the plants have finished flowering. Don’t cut back to the wood. Instead, cut off the old flower stalks and a further one or two inches of this year’s green growth.

I have only had a poor crop of thin and weak rhubarb. It is growing in a container that is 14" wide x 16" deep. Please can you advise do I need to replant?

Posted 10/07/2015 by Rosie, Wales

Hello Rosie, I’m afraid that rhubarb is one of those crops that prefers to grow in the ground. Relative to other plants, rhubarb produces an enormous quantity of foliage and thick, juicy stalks, so it needs to feed and drink accordingly. It also has a large root system that helps it to find and store enough nutrients and moisture to support all this growth. The best option would be to replant it in the ground with some farmyard manure added to the hole. If you have to keep it in the container, you could repot it into a John Innes number 3 compost. Water it well after planting, and make sure that the compost is kept moist for the next couple of months. But don't drown it so that it is soggy — you don't want the thick fleshy roots (called rhizomes) to rot.

I’ve noticed that the leaves on my lavender plants in the garden have started to turn yellow. The plants are about four years old and were potted from smaller plants into the flower bed. I’m not sure what the yellow leaves mean or what I should do?

Posted 29/06/2015 by Siofra, Co Monaghan

Hello Siofra, Yellow leaves are a sign that your lavender is stressed. Lavender is a Mediterranean plant, and it grows best on well-drained, neutral or slightly alkaline soil in full sun. If your soil is typical of Monaghan, then it’s probably heavy clay, and the roots are smothering. If you really want to grow lavender, you’ll have to take out the plants and dig in grit or gravel to lighten the soil and help with drainage. Even so, the plants may have to be replaced after three or four years.

Hi there, I’m thinking of investing in a compost bin for the garden – it probably wouldn’t produce that much compost as there is just my wife and me at home now. Is it possible to mix the compost we’d make at home with a bag of compost from the garden centre?

Posted 29/06/2015 by Bill, Co Cork

Hello Bill, I highly recommend a compost bin. Besides the waste from your garden, you can compost all your uncooked vegetable waste, pet hair and the contents of your vacuum cleaner. You can compost torn-up paper as well: corrugated boxes, newspaper and loo roll cores. Paper is useful if your compost is too wet and sludgy. And yes, it is fine to mix your home compost with compost from the garden centre. Just be aware that your own compost will have different nutrient levels from a carefully-formulated commercial compost. You can also use your compost to increase the organic matter in the soil, or as a nutritious mulch for plants.

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