Monday 28 October 2013

Gardening transformed. Herbaceous borders do not have to be high maintenance.

Even when planted this border has never been dug

I have hundreds of square yards of herbaceous perennials in my four acres of cemetery gardens which I maintain with an average labour input of two hours per week. I use some of my methods in my own herbaceous borders.
My friend Isobel had magnificent herbaceous borders. As she gets older - she is younger than me - to reduce garden maintenance, she is converting to growing roses! I am very pleased about this because as a result she has given me some magnificent herbaceous plants. Her superb peak season, colour co-ordinated borders, hugely acclaimed on her Open Day, used to take many hours to maintain. 

Why herbaceous borders are traditionally high maintenance.
It is important before you plant a herbaceous border that you eliminate established perennial weeds. Most gardeners fail to do this and subsequent weed control becomes nye impossible. Many gardeners accept divisions of herbaceous plants riddled with couch and ground elder from ‘kind friends’. These weeds have a way of taking over.

Most gardening books advise deep cultivations before you plant, to dig in huge barrow loads of farm yard manure and to leave fallow for the first winter before Spring planting.
Weed control in traditional borders involves laborious forking and hand weeding (or hoeing under more enlightened management). You might not believe this, but some gardeners actually dig their borders in Autumn!

Most gardening books recommend replanting every three to five years. Absolute nonsense, but I can understand why when rubbishy lanky spreading mildew ridden michaelmas daisies wander all over the place and lupins self seed vigorous purple offspring. Don’t get me wrong, many varieties of asters are my very favourite plants. I love lupins too but they are  very high maintenance. There is a ridiculous idea that clumps need to be divided because their centers become moribund. Once in a blue moon this will be true but I have yet to divide a herbaceous perennial for this reason. Of course vigorous plants do have a tendency to out grow their space and need to be reduced…
Some plants such as primroses and polyanthus do respond well to regular division. I grow these elsewhere in my garden.

Staking perennials is a skilled and time consuming job. Not only does inserting bushy supports need to be carefully timed and synchronised with plant growth they need to be carefully removed when the plant is cut back in Autumn. Some gardeners insist on staking all their herbaceous  plants. I remember years ago in a famous park in Leeds where even Dicentra formosa was supported. As holder of the National Collection I shuddered.

I do not stake any herbaceous perennials plants in the cemeteries but of course it does not matter if they flop everywhere!

Cutting back is an extremely labour-intensive task and if as I do, you believe that every ounce of beauty should be extracted from your plants before you prune back, the process needs to be spread over a long period.

Many herbaceous borders are riddled with powdery mildew, have slugs on the hostas, caterpillars and aphid. I never spray  against pest and disease in my herbaceous borders but many gardeners find this necessary… 

And we have not even considered watering, adding organic matter and feeding!  All this angst and hard labour. And after three years you need to do it all again. Not for me, thank you.

Better quality borders with much less labour.

On a new site eliminate perennial weeds before you plant using glyphosate. If in a new garden this takes a whole season start a lifetime’s policy of not letting germinated weeds seed.
Do not cultivate other than to adjust levels. Unless it is compacted by previous bad management do not disturb the existing soil profile at all. I am particularly addicted to making new borders by direct planting in a grass sward killed a few weeks earlier by a glyphosate spray. Why destroy wonderful  soil structure? I have been planting into dead lawns for clients and in my own gardens for many years now!

I am planting Cathi’s garden next door and am reshaping the borders to ease mowing

Best to plant in early Autumn and get the plants off to a good start in warm soil. However  where necessary and with appropriate management you can plant anytime. The only time I water my plants is when getting them established. I never water my established borders but of course in a very dry summer period an occasional very thorough soak with more than an inch of water is a beneficial option. Never faff around watering established plants with frequent applications of small quantities of water.

You must of course design your borders. Personally, I am incapable of drawing but do have the advantage of having a large stock of plants and divisions - knowing my plants intimately, I design as I plant. You will never get things completely right the first time and be prepared in the first few years to make small adjustments. This is best done at the time you can see something is wrong.

I am pathologically opposed to staking. I never stake plants in my cemetery gardens and  at home I can count on the fingers of one hand the occasions when Brenda insists that a delphinium, helenium or peony is given a cane or a loop of string. I prefer to plant bold self supporting clumps that grow sturdily in good light. Plants drawn as a result of poor light due to close proximity to buildings and hedges or planted in too narrow borders might need supporting in some gardens. I admit I am lucky to be able to plant in large self supporting clumps. Where small clumps of tall plants are planted, staking is more likely to be  needed. My garden has no special wind protection and is very windy. My plants grow sturdily in response to wind stresses right from first emergence and stand like soldiers even in gales. After exceptional very heavy wind it might take a few minutes to tidy the odd broken shoot but this will be no more (and frequently less) than those gardeners with their mental crutch of a crutch!

 None of these perennials are staked

It would be a shame to stake elegant Verbena bonariensis

Excellent weed control is fundamental to low maintenance borders. Throughout this blog I extol a ‘little and often’ approach to weed control. In my glyphosate post last week I described specific aspects of timing and directional spraying to make weed control in herbaceous borders efficient and easy. In my own borders I spray around herbaceous clumps with glyphosate and if necessary, hand weed amongst delicate new shoots. I sometimes lightly hoe. 

Some herbaceous plants such as helianthus and eupatorium are thugs and without appropriate attention tend to take over and swamp less vigorous plants. You need to adjudicate in this battle. I frequently do this by chopping out pieces to plant elsewhere. Sometimes this is insufficient. A weed is a plant in the wrong place and where my herbaceous perennial has spread too far I spray its invading advancing front. I am totally ruthless but a visitor to my garden is unaware that I sprayed early in Spring as shoots emerged or sprayed portions of the tops at the end of the season a few weeks before the plant’s natural senescence. 

Emerging spring shoots of helianthus have been deliberately sprayed and will die. If I have fastidious visitors I can hoe these yellow shoots off now. Do not try this with delicate plants.

This simple example is on ‘Gardeners Garters’ in late Autumn, the method is of greater value on thuggish miscanthus and elsewhere, bamboo! The dead sections make nice autumn colour!
I generally try to avoid planting pest and disease prone plants and am remarkably tolerant of light infections and await normal health to be restored by natural control as predators and parasites devour pests such as aphids. Because my borders are mainly island borders they receive plenty of light and do not much suffer from fungal disease. Other than my glyphosate I never spray!

I have been trying to convince readers that minimum cultivation creates very healthy soil. I hardly ever find it necessary to fertilize herbaceous  plants. Should your soil be less fertile than mine, top dress with general NPK fertilizer - perhaps in March. Just scatter it, don’t damage the soil and plant roots by working it in!

Cutting down herbaceous borders with secateurs  at the end of the season is very hard work, back breaking and boring. I have been cutting back with a petrol driven hedge cutter for many years now. The technique is now starting to become popular in public gardens. I find I can cut very close to the ground and get a very tidy finish. In my cemetery gardens I shred the tops as I cut and leave the trimmings as a mulch on the surface. Management here does not permit this untidy refinement which I only get away with in parts of the garden Brenda rarely visits. You will probably be horrified that sometimes I flash burn the cut tops in situ on the surface of the border. I would argue that the char is beneficial..

Before and after

At Boundary cottage my herbaceous borders are at least ten years  old. They will outlive me before they need replanting.

It would not be as much fun if I did not sometimes add a few extra plants


  1. My borders are too small to be classed a herbaceous borders but I rarely need to weed amongst the perennials - I think close planting helps though. Your borders certainly thrive on whatever treatment you give them!

    1. Yes Sue, I thought of making this point, so thanks for the reminder, Actually as some of my pictures suggest some of my clumps are quite wide apart but within the clump plants become quite dense. I specifically made my post relevant to a more traditional type herbaceous border but like you I use herbaceous perennials in many different ways.

  2. As I've just dug a hole which I'm filling with newspaper, I better finish that experiment first!

    I've also been experimenting with cardboard. A large piece of plain brown cardboard over the grass/weeds you want to replace, with some bricks to hold it down - these can be removed once it's got soggy and bedded in. It needs a cross cut in the middle for your plant, and some bark mulch if you want it to look a bit nicer. But only really suited to small areas, it would be quite a faff for a whole bed. I don't know yet how long it will take for the cardboard to disintergrate, I'm hoping the weeds will have died by then. I think the oxalis might survive though!

    1. I appreciate the irony of your first comment.
      I think fairly thick layers of cardboard have potential for weed control and many no-chemical gardeners use it - I am too wedded to my glyphosate perhaps.
      Where many gardeners who have perennial weed in the ground go wrong with this mulching method is that they don't keep at it long enough and it is essential that perennial weed does not get its green head above ground - otherwise it will always win the battle in the end.
      After a year or twos persistence it will work and of course if you only have weed coming from seed it is really good

  3. All my borders are a mixture of shrubs and herbaceous perennials and suffer from a shortage of light so I am limited to what I can grow. The poor light conditions tend to draw plants upward and can lead to spindly growth so, other than a top mulch of old potting material and maybe a light dressing of bonemeal most years I grow them mean on which they seem to do well. I do tend to let plants get too close together, in fact I almost "shoehorn" them in sometimes, which also encourages spindly growth but has the advantage of keeping them upright and avoids staking, which to be frank I am too lazy to do unless absolutely necessary and always in response to a plant collapsing.............. it's a fine line!
    Like yourself I use a hedge trimmer to cut back the debris, but I wish certain commercial gardeners would not also use this method to prune every shrub they can lay their hands on at the same time.
    Having pretty well eradicated all but a few perennial weeds, the main problem I have is from perennials seeding themselves into the crowns of others which, although I do try to keep a check on this by removing the seed heads of the known offenders, there are always some that escape. Luckily I do find hand weeding quite therapeutic.

    1. I do agree about pruning shrubs! And I do find various forms of weeding including hand weeding very relaxing. It is a mark of a good gardener to enjoy weed control. It means he is 'on top' and it brings him/her in close contact with the plants I am not a fan of bonemeal though! You mention she horning, the more I think about my bold clumps are actually quite a long way apart.

    2. sorry I meant shoe horning- must start using the preview feature!

  4. Intrigued with your comment about bonemeal Roger, I wouldn't say I was a fan myself but tend to use it because I always have done when I require a low nitrogen, slow release fertilizer which is readily available. I would be interested to hear why you don't like it as maybe I am missing something.

    1. I put bonemeal in my search box and found I had limited myself to only a few pompous comments about it! I will do a special post about it soon!
      Do read my posts via the search box on NPK and compound fertiliser to read something of what I think about fertilisers. The best I can say about bonemeal is that its use does little harm, where as the fertilisers I often recommend will, if put on too liberally

    2. Its me again Rick
      I am feeling a little guilty at not giving you a complete answer as to why I think that bonemeal is in my opinion a virtual waste of time. My objections revolve around the fact that for practical purposes it only contains phosphate. It does not even supply phosphate very well as most of the phosphate in it is not released for many years., It is the slowest release ‘slow release fertiliser’ I know. Most British soils have quite sufficient phosphate anyway as a result of years of excessive application of this nutrient that the soil naturally stores. On a really good day bonemeal contains 4% nitrogen, in scientific terms a piddling amount! Bonemeal contains zero potassium. It is generally considered that if you are applying the three most important nutrients they should be in some kind of balance for healthy growth.
      Unlike the multi nutrient general fertilizers I recommend bonemeal contains no useful magnesium, calcium, sulphur or any trace elements. Frankly in a natural material the fact that the literature gives no credit for these nutrients being present in bonemeal surprises me, surely there must be some calcium there?

      It has always puzzled me why amateur gardening pundits recommend bonemeal for any plant you may care to mention and yet I know no commercial grower who uses this material for any.
      The popularity of bonemeal is one of the biggest garden mysteries I know!. I rationalise the situation by considering that gardeners feel the plant needs extra nutrients (even when it frequently does not) and they must apply something when they plant and sow. When you apply bonemeal it smells so strong you must be doing good! Better, the gardening pundits can safely recommend it because it does little harm even when applied in ridiculous doses.
      As a final riposte although I say it is save to plants and I would agree save to the user, the mad cow disease scare did it no favours nor the historic fact that it could have once contained anthrax. I used to train garden centre staff in Dublin and at that time it was actually banned there!


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