Question time with Lou, Steve and Gary.

One of the best attendances of the year assembled for this meeting; not surprisingly, given the wealth of practical advice on offer, and who was giving it: Steve Edney, long-time patron of the Society, Louise Dowle, joint proprietor with Steve of the No Name Nursery in Sandwich and Gary Bradbury, Chair of the AHS committee, an agronomist with decades of experience. Here is a summary of the questions from the audience and the panel’s responses.

Q1. What, if anything, can be done about horsetails (a.k.a. mares’ tails)?

The short answer to the question of is there a cure in No. One or two companies have products which they claim can deal with these invasive plants, e.g. Neudorf’s ‘Super-fast long-lasting weedkiller’, which shows horsetail on the label. But without chemicals, every time you see it growing, pull it up or quickly cut off the shoot. The main problem is that the roots go very deep – they have even been found in coalmines, apparently. Most importantly, don’t let the plants produce spores. Thanet weed, which propagates itself from its roots, is dealt with in a similar way. Herbicides can work, as it has a coarse leaf, unlike horsetails, which have a silica coating so that liquid runs off them. Bindweed can also be controlled like this; a tip from Wisley was to put canes in the ground for it to grow up, then paint herbicide on it, which avoids spray drift. Controlling these vigorous weeds is going to take time.

Q2. Can apricots be successfully grown around here?

Yes. But variety is important. Steve and Lou have grown King Alfred and Tomcot and last year got around 20Kg. This year has been poor in comparison. They are best grown against a sunny sheltered wall. They flower early, before many flying insects are around, so you may have to use hand pollination. Stone fruit trees such as these, and also plums and cherries, need summer pruning, to alleviate bacterial infection. This is best done before the end of July, when it is dry, never during or after rain. Pruning tools should be cleaned before use, and between trees.

Q3. Any tips for plants that will thrive in the changing climate?

The trend is for wetter winters and hotter summers with more intense and frequent heatwaves. At The Land they have planted a grove of trees from around the world, to see which ones will thrive (and which won’t). A drooping conifer succumbed to the winter wet, after six years. One tree that is promising is the Golden Rain Tree, which is drought tolerant and needs very little soil. There is a book, Drought friendly plants (by Tony Hall), and Beth Chatto’s dry garden book; most of the plants featured in this will grow well in this area. Instead of just thinking about the Mediterranean/dry garden scheme though, it is possible to engineer good conditions for a cottage garden using trees and shrubs to provide shade and lower the temperature. An American book, Planting in a post-wild world, contains a lot of useful information about establishing thriving plant communities in these conditions. Steve stressed the need to acknowledge the interaction between soil type and climate when choosing plants. Lou recommended going to specialist nurseries for advice, and to buy online. Gary urged us to plant more trees to create dappled shade. 

Q4. Silver birches are very fast growing. Do they need to be removed from a garden?

They are a native British tree. They are susceptible to diseases and rotting, and can become unstable as a result. They must be pruned only in summer. It is a good idea to raise the canopy by removing lower branches, to allow the wind to blow through and produce less dense shade. It is very easy to get this wrong, so consult an arboriculturist. Other kinds of veteran trees can be left after damaged parts are removed: these parts can act as wildlife havens. Make sure your house insurance covers your trees: you are liable if one falls over and damages someone else’s property.

Q5. (An online question) Vermiculite and Perlite: what is the difference between them and how should we best use them?

There’s no consensus on this: people use them differently. Lou uses Perlite for cuttings and Vermiculite for seed sowing, to top off the seed tray when you might need to let light in. Steve agreed with this. Gary added that he uses Perlite a lot, particularly early in the year for seed sowing, to get some more air in the mix. Vermiculite is much more water retentive. Both aid in drainage, particularly with peat-free compost.

Q6. (Online) How best to prune plants such as Ceanothus.

Ceanothus should only be lightly pruned, straight after flowering: too much can kill them. Choisyas, being fast growing, can be pruned at any time. Older shrubs are less resilient to hard pruning. Mulching helps them to recover well. Lou urged the audience to invest in a pruning book, such as the RHS pruning and training book, to avoid costly mistakes.

Q7. Black patches of rot at the end of tomatoes.

This is blossom end rot, and has been a particular problem this year. It results from calcium deficiency in the growing cells. On very hot days, plants partially shut down, which slows the transport of calcium through the sap and it does not reach the further distant parts of the young fruits. It is often a problem with smaller greenhouses, which should be shaded in some way; the are too short, so the hot air is trapped too near the trusses. Misting the plants can help. Varieties with bigger fruit can be more susceptible. 

Q8. (Online) Could the panel recommend plants for a raised bed that would not grow too tall (>1m)?

It is in full sun most of the day. Berberis is possible, and useful as a barrier. For toughness, pyrocantha: it is a very useful barrier, and provides spring flowers and autumn berries, which attract bees and birds. It is very easy to grow and to find. A good arrangement is to pick three plants and plant them in threes, for added interest. An ornamental grass, such as the African Love Grass, would complement these two shrubs. It has a scent, like coriander. Plant in the autumn and mulch well. Neil Lucas’s book, Grasses for gardens and landscapes, is a good resource. 

Also at this meeting, the results of the potato trial were announced. There were twelve entries. The highest yield was achieved by Helen Higginson with 2.93 Kg. Runner-up was Sue Anstey (1.9Kg), 3rd place Janet Searle (1.5Kg). Gary advised that the number of shoots (chits) remixing on each seed potato when you plant it determined the size of the potatoes produced: the more that are left on, the more smaller tubers you will get.

Ken Manktelow