summer – Charlton and Blackheath Amateur Horticultural Society

Pat’s 10 jobs for September 2025

1. Well at last the rain has arrived and is ready to drown all our plants! You may need to empty those saucers you put under pots for some of your more tender plants before they drown or rot…

2. This month and next is a good time to cut down and split many perennials ready for our sale at the Horn Fair on 19 October which soon comes round. I split sedum and Hesperantha the other day. I needed two forks back to back but made about fifteen plants! Check which plants are suitable for splitting in Autumn as some are better done in Spring.

3. Increase your supply of Pelargoniums by taking cuttings now below a leaf node. It also provides insurance for next year. We always love unusual varieties for the sales table if you can spare them.

This Aeonium will not like sitting in a saucer of water! — Don’t let your pots drown! Geranium clump ripe for division, and Pelargonium cuttings

A clump of Geranium macrorrhizum ready for division — Don’t let your pots drown! Geranium clump ripe for division, and Pelargonium cuttings

August/Autumn Show 2025

The 2025 Autumn ‘Flower, Fruit and Vegetable Show’ was held on Monday 18 August in the Old Library at Charlton House.

As it is usually held in September, there were some adjustments to the range of classes. It was a well attended and lively show, and our fears that perhaps there would be fewer entries – due to the date change or the fact that we have had such a long period of drought – were unfounded. In fact, across the 18 classes there were 150 entries and we had to extend the show tables!

As this year is a special one, in which we celebrate the 75th anniversary of CABAHS, there were a couple of ’75th anniversary’ themed classes, and we were delighted to welcome as judge Jillian Smith, long-time CABAHS member and Chair of the Society, and now joint Vice President with Ron Roffey. Jillian has a long experience in judging shows over many years and has a beautiful garden in Winn Road, which was opened to the public on a number of occasions to raise money for charity.

Plants of the Month: The Oranges! (August 2025)

Rosa glauca garland, with hips — Rosa glauca adorning a pergola

After a brilliant summer, autumn is not too far away and this is when we start to notice more and more orange-flowered plants and berries becoming features in gardens and parks. Orange is a warm and comforting colour, and I’ve listed three that you might be interested in:

Pat’s 10 jobs for August 2025

1. Time to trim back lavender hard if it has finished flowering, but try not to cut into the old wood. If you’re lucky you may get a few late flowers.

2. And time to give that Wisteria and Campsis a hack back by removing all the whippy growth and tidying up for the autumn.

This lavender will need a cut back soon. — Promote flowers by cutting back and watering in good time.

Camellia flowering in Spring. — Promote flowers by cutting back and watering in good time.

3. Azaleas. Camellias and Rhododendrons are making their flowers for next year and need regular water at their roots or they’ll drop their buds and have no spring blooms.

July 2025 Meeting and Show Table

Lots of variety on the Show Table this month, just as we like it! The Show Table is a chance for members to bring in and display plants and flowers that are performing well in their own gardens each month, be that a single flower / stem / fruit / vegetable or a display of all that is looking good – or indeed something in between. It’s lovely to see what people are growing.

Plants of the Month: The Whites! (July 2025)

My garden is looking past its best now, as the heat-waves and lack of rain having taken their toll, but these three plants are looking stunning and all worthy of the status of Plant of Month for July 2025.

Mandevilla laxa (Chilean jasmine), July 2025 — *Mandevilla laxa, Hydrangea quercifolia,* and *Clematis* ‘Kaiu’ (V): the whites for July

Hydrangea quercifolia (oakleaf Hydrangea), July 2025 — *Mandevilla laxa, Hydrangea quercifolia,* and *Clematis* ‘Kaiu’ (V): the whites for July

Pat’s 10 jobs for July 2025

1. If herbs like thyme have finished flowering, trim them back to keep them compact and use the trimmings to do some cuttings.

2. Stake Dahlias before they get too tall and straggly or the stems may snap. Keep well watered in this dry weather.

3. To conserve water and before we get a hosepipe ban, just water around the roots of plants and mulch them if you can. Some are really suffering at the moment. So why not start sowing seeds of Eryngium giganteum ‘Miss Wilmott’s Ghost’ for a drought proof plant for next year? Loved by pollinators too.

Eryngium giganteum 'Miss Wilmott's Ghost' at Great Comp, covered in pollinators — Drought resistant plants that pollinators love: *Eryngium* and *Pseudodictamnus*

Bee on Pseudodictamnus mediterraneus (formerly Ballota) — Drought resistant plants that pollinators love: *Eryngium* and *Pseudodictamnus*

What to look out for in the Old Pond Garden July 2025

Penstemon ‘Garnet’ – Beardtongue

Although at its peak in July, this has been out since May and is one of the longest-flowering plants in the Old Pond Garden. At the moment we really love it for it’s drought tolerance – no need to water this one! It has dainty, tubular flowers which insects with long tongues like bumblebees can enjoy, and it provides both pollen and nectar for visiting insects. Prefers a sunny spot but will do well in part shade too, so you can spot it in several of the beds. It is a semi-evergreen, only losing it’s leaves in the very depths of winter.

Dianthus carthusianorum – Carthusian Pink

Another lovely drought-tolerant plant that we don’t have to water! It must be in full sun to flower well, so it just loves the gravel garden in the central bed of the Old Pond Garden. It’s a perennial, forming bigger clumps each year and giving that great “pop” of colour. A gentle self-seeder and long season in flower.

August Flower, Fruit & Vegetable Display 2025 – classes to enter

This year’s Autumn Show will be held a month earlier than usual, on Monday 18 August, at 7.30pm in the Old Library at Charlton House.
Please note that due to the earlier date, the Potato competition will be judged as part of the Show Table at September’s meeting.

Here’s a reminder of last year’s efforts!

Whole table of entries, Autumn Show 2024

The classes you can enter this year are shown below, please have a go at as many as you like!

June 2025: Gardeners Question Time

This is now a regular and popular event in which our panel answer questions sent through in advance from members, some with illustrations or examples sent in plastic bags. The panel this year consisted of our very own CABAHS committee member and all-round plant guru Pat K, our President Sir Nicolas Bevan and horticulturalist and teacher Joe Woodcock. Sir Nicolas invited advice and contributions from the audience too, saying that in a room full of gardeners, the panel did not “have the monopoly on wisdom”. We did our best!

Our 'Amateur Gardeners' Question Time' panel, June 2025 — Our esteemed panel: Pat, Nicolas and Joe

Last year we were all overwhelmed by slugs and snails, this year’s scourge is aphids! The first question related to a particularly damaging infestation on Buddleja, which seemed to have caused a virus. Several people, including Joe, have experienced the same this year. He was able to tell us that it is likely to be a specific species, the Melon-cotton aphid, which the RHS are monitoring (you can report cases to the RHS here).