How we're planting for climate change at Ham House

The longest and widest border at Ham House and Garden is south facing, in full sun. It is sheltered by redbrick garden walls all round and with the historic house at its centre.

Three years ago the display of 17th century planting included a selection of period plants that might be described as 'woodland', they were able to thrive in shade. In the last three very warm summers these plants, including the elegant and useful ground cover Saxifraga × urbium or ‘London Pride’, have declined and died. Increased heat levels combined with drought is our diagnosis.

New plant selection, the old-fashioned way

Now we are developing this border by planting the horticultural by-products of the ancient spice trade routes - like cannas and agaves - and these are thriving. Somebody described it as 'your exotic border': although to me these plants don't feel exotic. They have survived South West London winters since the Thames froze in the seventeenth century, lifted and coddled or not.

While we are adapting to today's conditions, this is still gardening based on 'right plant right place' (conditions) plus period selection (historic) and an over-seeing creative eye (unrealistic aesthetic demands of current head gardener).

Can our trees cope?

As well as the extreme heat this summer, we had to shut the garden and house due to forecasted high winds. This decision was based on our assessment of how well its many trees could cope with the conditions, given that they are in an area where public footfall is high. We are not used to gust speeds reaching almost 50mph in August and neither are they.

It's the change in general conditions like these that is posing me most concern. In my experience, we have less knowledge to apply now when it comes to plants' behaviours and responses to the weather. Adapting our planting is a challenge that the team at Ham is keen to meet though, and there are positive stories to tell our green-fingered visitors.

In the walled kitchen garden, the apricots, plums and cherry trees thrive with occasional drench watering and thick mulches. Our apples are showing summer burns after short, very hot periods earlier this year.

If you are thinking of planting a new fruit tree this autumn, south and west facing sheltered, sunny sites might not be the future-proofed answer for apples. Here we are looking at companion planting that offers some sun-shade

Fruits of a longer season

The long-term implications of the projected weather patterns we expect to see at Ham House keep my thoughts often in 2050. We have predictions of summer temperatures often over 40º, overall reduction of annual rainfall and extremes within short, unseasonal timeframes. New permanent planting, especially of trees, has to take this perspective into account.

On a lighter note, at home and at work I'm allowing myself to enjoy some benefits. Savouring outdoor ripened aubergines, chillis and a long tomato season I could get used to. Our kitchen garden planning has new opportunities. A Mediterranean diet is a Ham-grown possibility.  Dahlias are flowering to at least the end of October.

A fresh gardening calendar?

Daily routine has actually changed already. We keep an eye on trees from May and for fruit (our sun-drenched quince, for example), we water using our own harvested supply to ensure yields are not compromised. We expect to water our box topiary and hedges too.

As the garden custodian here, with 400 years before me, I'm now trying to apply a climate change perspective to every single action. It's a new, vital future view that makes my head spin. I’m developing some basic principles for our planning that will make the head-spinning reduce though and the proactive, pre-emptive approach that the garden needs take over.  When they are ready, I’ll share them with you!