August in the Garden

Gardens have a memory. What is happening in your garden, on any particular day, is not just a reflection of the prevailing conditions but also of factors that have influenced it over the whole time it has been in existence. The factors affecting plant growth / survival are cumulative and can either be very subtle, acting over a long time, or, such as in the case of catastrophic weather events, very dramatic and immediately obvious.
There are certain things that are performing much better this year than I can ever remember them doing previously; Acanthus mollis (bear’s breeches) being a case in point. Originally mine were planted right up against the house which, being poorly built after Victorian subscription, has no damp course or ‘real’ foundations. Acanthus is so massively rooted that it was in danger of coming up through the floorboards on the inside of the house! That was almost twenty years ago—I dug it up and moved it, to a restricted position on the road side of the curtilage, and it has been there, totally uncared for, ever since.
It is in poor soil, exposed to winter cold, but, importantly, it gets a total baking in the summer sun plus extra root warmth due to the brick retaining wall which absorbs heat during the day and releases it over night—just like a storage heater. Over the years its flowering has been fairly ‘up and down’. Last year, during what was a relatively hot and dry summer, it flowered ‘OK’—nothing special. This year it’s flowering its socks off, one of the best displays it has ever produced.
This is not because of the recent warm weather, it is the cumulative effect of the weather and cultural factors that have acted on it over the last two decades that it’s been under my care. The heat last summer was the biggest factor in determining that it should be putting on a ‘career best’ performance now. I expect that next year, having partially exhausted itself, it will not flower so well—whatever happens in the intervening period. Knowing that it comes from places with relatively poor soils influences my decision in what to do next. If I tried to feed it, by adding a fertiliser for example, to address the ‘exhaustion’ I know that it would react, being a bit of an opportunist, by producing lots of extra leafy growth. This would actually reduce its flowering potential for next year.
A more ‘greedy’ perennial plant, lilies grown in borders for example, need copious feeding after flowering, while still leafy, in order to build up the flowering potential for next year. If I treated my floriferous herbaceous perennials, in the same way that I treat the tough old ‘bears breeches’, then they’d never flower again and might actually fade away. It’s all about ‘horses for courses’—and understanding what you are dealing with.
The point of this is that gardening is a long-term pursuit, the horticultural equivalent of ‘spinning plates’! I often bang on about certain gardening tasks, like watering / feeding plants that are confined to pots and containers, because they really do need to be done, in a timely fashion, or else the plants will soon die and any long-term, cumulative, factors become completely irrelevant.
The whole “Right Plant, Right Place” philosophy is perhaps the most important horticultural maxim that anyone attempting to garden should try to master. The late, and great, Beth Chatto was the greatest exponent of this approach to gardening and her writings on the subject cannot be bettered. Planting the right plant, for the conditions that you are expecting it to thrive in, is the best route to allow it to gain maximum benefit from it’s place in your garden. Getting that bit right really takes the pressure off you, as custodian, in every cultural intervention that you will do over the whole lifespan of that plant and, by extension, over the whole life of your garden.
The fact that my Acanthus is flowering so well right now, and not coming up through the floorboards of my front room, is because I was able to recognise that its thug-like roots are best contained within retaining walls. Its origins in hot, baked, climates mean that repositioning to a south-facing position gives it the best chance to fulfil its maximum flowering potential whenever it can respond to a favourably hot summer. This may be an extreme example but I’m trying to explain that if you get these things right in the first place then it makes your life so much easier for the long haul.
On a more general note; shrubs flower best on wood which has been ‘ripened’ by the sun the previous year, so they may, like my thuggish Acanthus, show the effects of the previous year’s conditions rather than the current ones. On the other hand, shrubs which flower after the longest day tend to flower on shoots grown that year so they will be less affected by what took place the previous year and will reflect their current growing conditions more religiously—I think I may quit there because I’m managing to confuse myself…
Containers may well have to be watered and fed this month to keep bedding plants and annuals flowering for as long as possible. Unless you added a slow release fertiliser to the compost, when you planted them up, there is a good chance that the containers will have had all their nutrients exhausted by now. When watering towards the end of the growing season use a ‘high in potash’ feed, such as tomato feed, as this is biased towards flower and fruit formation rather than excessive leafy growth; the last thing we need right now is more soft, green, growth.
This is the best time to plant bulbs which flower in the spring. It may seem very early, and a bit depressing to have to consider the end of summer just as things have started to hot up, but it really is best to get them in as soon as possible. Tulips are the exception to the ‘plant now’ rule, due to cultural reasons (‘Tulip Fire’) but if you order them now at least you get first pick of the crop as the most popular / newest varieties (for me it’s always ‘Abu Hassan’) sell out quickly.
The horticultural reason, for getting hold of spring bulbs now, is to reduce the time between the bulbs being harvested by the grower before getting re-established in your own garden / pots. Although they are happy to become ‘comatose’, once harvested, all the time that they are out of the soil, even if stored correctly, they are deteriorating. The smaller the bulb the more prone they are to dessication between lifting and replanting—this is the major factor behind tiny bulbs, such as snowdrops, generally being recommended for planting ‘in the green’.