Les’ Patch: Answers to your gardening queries

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I thought it would be a good idea this week if I looked back on some of the questions I have been asked when giving talks.

At the same time I hope some of the answers will help with any problems you may have.

Which shrubs are suitable for seaside gardens?

Calluna vulgaris (heather), ceanothus (California lilac), hydrangea, viburnum, euphorbia, ligustrum (privet), prunus, pyracantha, rosmarinus (rosemary), chamaecyparissus (cypress).

I also have euonymus, holly, osmanthus, potentilla and elaeagnus which I grow in the open in the salt winds. Obviously there are many more you might get away with.

Which grass seed would you advise to use on a new lawn?

You are fortunate if you are sowing a new lawn in that if you choose the right seed you will do away with one of the worst lawn problems, and that is thatch (a mat of dried out grass leaves and stolon).

Some grasses are more apt to produce thatch than others.

Those that reproduce by stolons that travel along on top or just under the soil surface tend to create most thatch. In contrast other grasses rarely product thatch. So when buying grass seed ask at the garden centre for the thatch-resistant variety.

What is the ideal pH of garden soil?

If the pH level of your soil, its acidity or alkalinity, isn’t right, you will encounter severe problems as it affects everything else about the soil, from its microbial population and structure to its drainage and the nutrients that are available.

Neutral soil has a pH of seven, but for most garden plants the ideal soil has a pH between 6.8 and 6.5, that is one that is just slightly acid.

Most of the plants you will grow will tolerate soils more acid than this, but when there is a pH below six you are likely to see a few problems.

Acid soils interfere with nutrient absorption by plants because they make some of the trace elements excessively available.

Manganese-boron and aluminium compounds are toxic to plants, and plants often take up manganese and boron in preference to some of the other nutrients they need.

This results in deficiencies of nutrients such as nitrogen and phosphates. Soil micro-organisms can also be adversely affected.

Without high diverse organisms, organic matter cannot be changed into forms that are available to plants and the soils capacity to hold both air and water diminishes.

For all these reasons it’s wise to correct pH problems before they become severe.

For those of you that know me this is probably the first time you have heard me being technical, but there is no other way to explain the importance of the correct pH.

You can buy a pH tester for around £10 at a garden centre. I will explain how to correct the pH in your soil in a later column.

What is the best way to deal with a fungi attack such as mildew and rust?

Fungi reproduce themselves by means of airborne spores.

The most important thing to remember is that fungicides don’t actually kill fungi but prevent the spores from spreading.

At the first sign of a fungal disease prompt spraying of the whole plant and any others of the same type standing nearby will provide protection from infection.

Also spray early in the season any plants that are susceptible to attack, such as roses.

A protective coating of fungicide on the leaves will ensure that any fungus spores that land do not infect the plants.

What can I do to overwinter hardy fuchsias as I haven’t a really frost free area to keep them?

In this case put the plants back in 15cm (six inch) pots and bury them in the garden.

Make sure the tops of the pots are at least 23cm (nine inches) below ground level and then cover with a layer of straw and one of soil. Mark each spot as a reminder. You will find this method is a winner. Lots of gardeners do this with their dahlia tubers.

What can be done to protect raspberries from disease?

These diseases are spread by aphids so the solution is to spray early in the year using Provado Ultimate Bug Killer.

This is a systemic spray which means it enters the plants’ sap stream and protects the plants for seven weeks against pests.

So if you spray every six weeks you won’t have any problems.

But always remember that certain chemical sprays are not suitable for some plants so check the labels before use.