Home Sweet Home!

18 September 2023 14:09

©RHS/Jonathan Webster

©RHS/Tim Sandall

©RHS/Paul Debois

Early in the year, we moved the Alpine House from near the restaurant to the Croquet Lawn in Lady Anne’s Garden and re-christened it the Temperate House. Though quite small, this has given us the opportunity to grow a very wide range of plants that require the minimum of heat through the winter months and relish the heat and humidity of summer. Plants from different habitats can be grown successfully together as long as a few simple rules are followed.

It is always good to have ventilation, achieved by opening doors and windows when temperatures allow. During winter, damp air will produce condensation, providing the ideal conditions for fungal growth, causing a lot of damage to plants within a short period of time. Ventilation will disperse this condensation and moderate any temperature rises on warmer days, helping to prevent early growth.

A thermostatic fan/heater will help to circulate the air and add heat when temperatures drop below the desired minimum. In summer, it will moderate high temperatures and reduce the possibility of scorch. This air movement through the plants also produces stronger growth and can reduce the numbers of unwelcome visitors such as aphids and white fly.

Greenhouses can become incredibly hot on summer days particularly small ones, which have a much smaller body of air to heat up, because of this they also cool down much more quickly. Shading can help reduce the temperatures, reducing transpiration and watering requirements.

The siting of plants within the greenhouse is an important consideration. The plants themselves may give you good clues to their requirements but it is also worth reading up about them to make sure that their needs can be accommodated.

Generally, cacti and other succulent plants need plenty of light, some need careful summer watering but on the whole, if a well-drained mix is used they are easily pleased. It is winter damp that causes the greatest problems. Their fleshy leaves and stems are an adaptation to being able to survive periods of dry weather, some for considerable periods of time.

Cacti from the genera Rebutia are often true alpines coming from high altitudes in the Andes. They will grow well in a glass house with minimal heat, as long as it is free from frost. A dry winter rest is essential. Watering commences in the spring, and as temperatures rise they will start to produce abundant flower buds of oranges, reds, pinks and yellows well in to the summer months. Echinopsis are another genus with many species and hybrids suited to the same regime which can produce quantities of magnificent but short-lived blooms.

Ferns are a very diverse group and many would grow well under greenhouse staging enjoying the shade and increased humidity. Others are happier in lighter conditions, clues being those with glaucous (blue green) fronds or indumentum (woolly like scale covering) on the leaf surfaces which act like a sunshield.

Orchids are a hugely diverse group of plants that could fill any greenhouse space many times over with the massive range available. Often regarded as being difficult and requiring high winter temperatures, many people are reluctant to give these very rewarding plants a go.

If you fancy your own temperate house, the important thing is to research what will be suitable for the environment that you wish to create. Always try to find a few easier plants, these will enable you to build up your confidence and hone your skills while continuing to track down those more elusive specimens that you are craving.

Jonathan Hutchinson, Team Leader Lady Anne’s Garden

Tips for Sept/Oct

1. Divide herbaceous perennials. Dividing perennials regularly will ensure healthy, vigorous plants that will continue to perform year after year with the added bonus of multiplying your stock.

2. Collect and sow seed from perennials and hardy annuals. Growing plants from seed is generally straightforward and inexpensive (you only have to pay for potting medium).

3. In late autumn, cut back perennials that have died down but leave some stems to over winter to provide homes and food for wildlife.

4. When the first frost threatens, move tender plants into a greenhouse or conservatory.

5. In September, dig up remaining potatoes before slug damage spoils them.

6. Plant out spring cabbages in October.

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