Planting density - how close should my plants be put together

I sometimes plant in bold clumps (or unrestricted they become so)

I am indebted to Noel Kingsbury who has written a very fine post entitled ‘Mind the Gap’. He writes as a gardener and professional landscaper. In his case he looks at herbaceous perennials but I would like today to consider woody plants too.

Noel observes that although common planting densities for herbaceous perennials might these days may be 7 to 9 plants per square meter that even these  might be extended. We have evolved from Victorian grand isolation of ‘specimen plants’

I would like to have bold drifts of this one but on my soil dictamnus is somewhat miffy

As a gardener when I consider planting densely I think of the budget. As a Yorkshireman my garden has generally been extended one at a time!

I feel the urge to write a post about how easy it is to bulk up bought plants very quickly in improvised nurseries (buy big plants and divide them) - but not today!

Noel’s methods not only give speedy establishment of a new garden feature but he argues it is more visually acceptable to almost completely cover the ground and is ecological sounder. Some of his friends let annuals seed themselves and intertwine and so do I.

Quick results with annuals

It is particularly important if you are planting herbaceous plants densely you have tackled the perennial weeds. If your ground is invaded with such as ground elder, bindweed and couch you will never get rid of them if intermingled within a dense canopy.

Geranium macrorrhizum (under the tree trunk) provides superb ground cover

These hostas suppress weeds from seed too

On the other hand if you have an established perennial weed free complete plant canopy then weed control becomes much easier as most seedling weeds fail to establish. Indeed you can considerably ease your garden management if you plant areas of more vigorous recognised ‘ground cover plants’. My all time favourite for this is Geranium macrorrhizum.

Peter's borders are densely planted too

When I look round my garden I have fairly dense planting albeit achieved after several years of endeavour. It’s best to fill the borders and relinquish bare soil. 

I have varying styles. My herbaceous borders in Summer are almost impenetrable masses of perennial plants. My mixed borders are more or less isolated shrub and tree plantings with herbaceous underplanting and self sown annuals and short lived perennials. 

You can walk in and around

At times there are bare gaps where bulbs seasonally appear. Some perennials have a short season and they die down at different times. I like where possible to utilise such space more than once in the year and for example clumps of hyacinths are replaced as dormant dahlias appear in their place.

You can walk between the plants in Bolton Percy cemetery garden

Elsewhere I have several ‘walk in’ features mainly gravel mulched where the above principles also apply but there are more high-light requiring flat drifts of herbaceous and alpines in transient open spaces. Where clumped together surrounded by empty spaces there is less competition for water than in a completely dense planting. This is a design consideration in low rainfall places.

Planted as one small pot I have had to reconsider the border design as my tree heather has grown

In my ‘acid border’ shrubs such as azaleas scramble together and are under invaded by low growing plants and shrubs such as heathers. Noel would be horrified that my heathers over the years have been planted one at a time. Those of you with a more generous nature will plant 3, 5 or 7 (if you are fussy about odd numbers). Noel will probably plant hundreds.

Rather unruly

There are a few other places where my shrubs mass together to make elegant competing compositions - and Brenda walks round and declares she cannot define their individual outline and gets out the secateurs or orders me to prune out some branches. Indeed exuberant competitors do need adjudication - and that includes both of us too.

If a cold Winter kills my six year old bottle brush it leaves an empty space

The question is how we get from an empty garden to one of pleasing easy maintained maturity. It can take years and the best gardens develop organically. I never paper planned mine.

Woody plantings

It is inevitable if you are planting slow growing shrubs that will take years to mature that you will plant quite densely to achieve immediate effect. If you move in to  an already existing garden do not strip everything away and start again. Leave existing plant structures for temporary shelter and beauty. You might find you keep some for ever. Wait to assess existing dormant plants.

Some of your shrubs at planting time might be more vigorous than what you eventually require. I have never quite understood the value of nurse planting where such plantings might protect slow growing neighbours.If you are not careful they are more likely to outgrow them. 

It is inevitable however that some of your shrubs will be slow growing and take several years to achieve their grandeur and might start off with more vigorous neighbours.

I don’t discourage dense planting for the short term but do encourage close monitoring and eventual thinning out by removal or reduction by pruning.

Love in a mist all over the place

A domestic problem I still have is that my plantings are littered with (in my view) beautiful annuals such as nigella, euphorbia and corydalis but that Brenda regards them as undisciplined intrusions. They do of course need careful management. I just bite my tongue when they are pulled out prematurely!

Somewhat undisciplined

They say not to put large plants in narrow borders but I do not agree

Link
Noel's blog gave me the idea to write about design today