Affiliation between RHS and Gardeners Association

The Royal Horticultural Society, to which the NLWGA is affiliated, is seeking closer links with associations like ours, were they are able to provide solutions to gardening problems that many of us amateur gardeners cannot. Furthermore, the RHS will advise on new problems facing gardeners (such as the spread of the New Zealand flatworm that devastates earthworm populations) and possible solutions. They are also seeking our help in gathering country-wide information.

Our committee member Malcolm Greenhalgh has recently taken on the role of linking between us and the RHS and below are some of the recent problems they have advised about. We will try and update the site regularly with further details. If you have comments or experience with any of these please feel free to add your comments by using the comment links. Hopefully we can all benefit from our affiliation with the RHS by learning that little bit more about the plants that we grow. We will collate and feed back to the RHS.

If you have experienced other gardening issues you would like Malcolm to take up with the RHS please email details of these to us using the email links below, and we will endeavor to seek their advice and post  response for all to read and learn from

RHS Membership can be yours at a discount price, and our Association will make a fiver if you do! Advantages: 12 issues of The Garden every year (the best gardening magazine); free entry into RHS gardens (as at Harlow Carr and Wisley); members’ day at RHS shows (e.g. Tatton); a free advice service. If you are interested, please contact Malcolm Greenhalgh.

Insectisides outlawed by EU

by Malcolm Greenhalgh on 07/04/13

Some major insecticides are outlawed by the EU. We ought to be careful with insecticieds, as they kill essential insects, such as bees, as well as nasties; and if we us them stupidly (as perhaps described by one of our speakers) even more will be banned. So spray with insecticide late in the evening, when bees have gone home to roost. Also be sensible.

I spray my apple trees to prevent damage by codlin moth, but use the pheromone traps to tell me when to do it (we sell them in the hut) but up the trap(s) and when you see about a dozen moths trapped on the sticky cardbaord spray THAT EVENING. then give them another spray exactly 14 evenings latter.

Native species of bulebell

by Malcolm Greenhalgh on 07/03/13

Introduced species of bluebell are threatening our native ones (species Hyacinthoides non -scripta) by interbreeding with them. Our native ones are far more interesting and stricking than the non native.; if you want to rid your garden of the latter then here's how to tell the difference.

In our native bluebell the pollen is white (blue or bluegreen on non native), the flower is "nodding" and most flowers come from one side of the stem (more erect and flowers from all around the stem), and the flowers have lovely perfume (the foreigners and hybrids have little if any perfume).

I have zapped one patch on non native with Glyphosate.

A note from Malcolm

by Malcolm Greenhalgh on 03/28/13

This March has shown the folly of trying to beat the Calender by sowing/planting tender plats too early. Why do local garden centres have plants such as tomatoes and bedding plants for sale so early? Perhaps so that the first lot will die and you will have to buy replacements. A couple of years ago I planted some early potaotes on 21st March and then another batch on the 4th April, and the April lot were ready for harvesting the same time as the early batch.


The problem comes from the TV and radio gardeners and writers who live almost exclusively in the deep south, where they dont get the rainfall and cold of our climate here Up North. So when they say , sow or plant at such a date in spring, give it another fortnight. And beware packets of seed that say "Can be sown in March". They could be sown on midwinters day, too!

Want to start an Asparagus bed?

by Malcolm Greenhalgh on 03/28/13

Its easy provided you get the soil right (well drained and on the light side .. put lots of humus into clay soils). An RHS study rates six varieties highly: Becklim, Connover's Colossal, Dariana Gijnlim, Guelph Millennium and Stewart's Purple.

Yet more foreign pests, brouht in with consignment plants.

by Malcolm Greenhalgh on 03/28/13

This time two very closely related species, the Asian and the citrus longhorn beetles, have arrived and are spreading. Their larvae feed on the heartwood of trees and shrubs and their tunneling weakens the plant, leading to death. The larvae have exit holes 6-11mm in diameter close to ground level. The adult beetles are unmistakeable: up to 37mm (1 1/2 inches) in lenght, with a black body with double white spots on the back and with very long, black and white banded antennae. Should you come across one, put it alive in a container for examination: these are notifable pests. The Food and Environments Agency (FERA) can be contacted on 01904 465625.

There are more "biocontrols"

by Malcolm Greenhalgh on 03/28/13

There are an increasing number of pest control organisms that means you dont have to use spray and other chemicals, and the newer ones will control vine weevil, whitefly, red spidder mite and mealy bugs. I find these a bit on the expensive side, but if you want to ne 100% organic they are indispensible. To find out more, go to www.rhs.org.uk and find "Biocontrols" for details including suppliers.

Insecticides are likely to become fewer.

by Malcolm Greenhalgh on 03/28/13

The EU (bless that wonderful beaurorcracy), pushed by the "greens" and with no scientific evidence, are trying to ban neonicotinoids, a group of insecticides developed in the 1980's, becasuse they might harm bees. All incecticides will harm bees if you spray them , so none of us should use them when bees might be about (if you want to spray with incecticide, do it in the latish evening when the bees have gone to bed for the night). And we should all seek alternatives where possible. But there are occasions when these seems essential, for instance in controlling codling moth in apples. The hormone traps catch the male and so reduce the problem a little, but there main use is to see when is the best time to use a spray. When the trap has caught 12-15 moths, spray that evening and then a fortnight or three weeks later and codling moth should be no problem. Watch this space

Putting Bits of broken terracotta pots at the bottom of plant pots to improve drainage

by Malcolm Greenhalgh on 03/28/13

My grandfarther, who started me off gardening over fifity years ago, taught me always to put bits of broken pot at the bottom of plant pots so that excess water will drain away quickly. Recent research, however has shown that this is not only unnecassery, but that there are far better ways of going about it. Apparentely those bits of pot do not aid darinage; instead they create what soil-water scientists call a "perched water table". In other words, the crooks do not enhance drainage, but they hinder it.


What they suggest as a far better approach is to mix plently of grit into the potting compost (since I read about this I have been putting one unit of grit to nine units of Sinclair, Clover or other non- soil compost .. it seems about right). I compared this with a large pot containing crock at the bottom and with pure Sinclair compost on top, and found that drainage greatly improved and that the compost was not so heavy and stodgy (i.e there was more air in the compost, and plant roots need lots of oxygen). Of course, with no crocks the plant also has more compost for its roots to penetrate. the grit we sell at the Hut is ideal.

Red Band Needle Blight

by Malcolm Greenhalgh on 09/26/12

Yet another disease has reached the UK and is spreading "Red Band Needle Blight". This affects conifers in the Genus Pinus (true pine). In autumn needles develop yellow bands and tan spots.; then the needles become red - brown and fall off. There is no chemical spray avaiable; RHS advice is to make sure that pines have plenty of air circulation, to prevent high humidity. So if you are going to plant pines, give loads of space.

Planting New Shrubs and Trees

by Malcolm Greenhalgh on 05/18/12

One member planted a new rose bush and reported that it wilted badly.

First of all, newly planted bushes and trees may wilt because the soil is watterlogged and the roots cannot get enough oxygen from the soil. So on clay soils make sure that the drainage is good.

Secondly, if the soil is OK, make sure that you give newly planted bushes and trees plenty of water, even though it may have rained. even here in the rain sodden northwest of England, newly planted shrubs abd trees will need extra until there roots have penetrated deeply

Recent problems and advice