Tag Archives: under planting

Tikorangi Notes: underplanting, gardening with perennials and the magnificent nuttalliis

Pretty Rhododendron Yvonne Scott (nuttallii x lindleyi x dalhousiae) with a named clematis but I have lost its name – relevant to the last para on this post and a prettier photo to lead with than the mishmash of a garden bed below 

Not good at all. The addition of roses was a particularly ill-considered decision

I spent a good four or maybe five days taking this unsuccessful garden bed apart. It was first planted about 14 years ago and the original idea was that it continue the theme of the driveway border – mixed shrubs with predominantly hellebores as underplanting. It has never thrived and over the years, its treatment has followed a pattern that many will recognise – random attempts to spark it up that have made it messier and more disjointed.

I lifted everything except the Queen palm (Syagrus romanzoffiana), an attractive Viburnum sargentii ‘Onondaga’ and Camellia minutiflora. The location is too sunny for the hellebores and they were not thriving, so I planted them elsewhere. And I found why the plants at one end had never thrived. I could only get the spade half way in before I hit what might as well be bedrock. It was the old driveway with very heavily compacted road metal. I recalled that Mark had got the nursery staff to plant that bed when it first went in. Now, our nursery staff were whizzybang at speed-potting plants and doing the hard graft of keeping a production nursery going but gardeners, they were not. I am guessing they chiselled holes just large enough to fit the plants in. No wonder so many failed to thrive. There was nowhere for them to get their roots down.

The aim is to have a carpet of harmonious under planting by the end of summer

I took out any larger stones and rocks I could get out, dug the soil and incorporated compost at a rate of a small barrow-load per square metre. There is still not a great depth of soil but what is there should be better and I won’t try growing any more deeper-rooted plants at that end. When it came to choosing what to replant, I fell back on my mixed border philosophy. When there is a mixture of shrubs in the upper layer, it is better to choose some uniformity in the ground cover layer. The opposite is also true: where there is uniformity in the upper layer of shrubs and trees, it is more interesting to use a mixture of plants at the ground level. It may be a sweeping statement (well, it is) to say that only landscapers, non-gardeners and novices go for regimented simplicity of matching upper layer plants and a single choice ground cover – tidy, visually effective in the immediate stage but essentially dull.

A totally reliable stoeksia that is particularly amenable to being divided and transplanted

Given the feature shrubs and palm are interesting in their own right and the presence of assorted seasonal bulbs, I chose to replant at ground level with the reliable, long flowering blue stokesia which thrives with us, a ground-hugging blue campanula and two forms of our native brown carex grass.  The upright form is Carex buchananii , I think, but I am not sure what the fountaining version of it is called. They are to form the carpet. I like the combination of blue and the mid-brown carex. Then I mulched it all. Now all it has to do is to grow.

May 2019

November 2019

It is quite gratifying to see how much the grass garden has grown since I planted it at the end of May. I am hoping that it will have closed up quite a bit by the time autumn comes. There have only been a small number of deaths amongst the plants – all were  Astelia chathamica and fortunately, I have more plants to hand that I can move to the gaps. The advice from colder climates is not to move perennials in winter because they are not growing and the risk is that the roots will rot out over winter. With our mild winters, this advice does not generally apply here but that may be the case with the astelia. The divisions all had roots when they went in but it may be that some did indeed just rot out before they came back into growth in spring.

My main task in this new garden is staying on top of the weeds. Considering it is new ground, there is not a big weed problem at all and I am determined to keep it that way as it gets established. Weeds getting a hold amongst the fibrous roots systems of perennials and grasses can be a maintenance nightmare. It is better by far to keep them out from the start, as far as humanly possible. Because it is all ground that has been freshly dug this year, it is easy to hand pull those pesky weeds that do try and make an appearance.

Eighteen months to fill in seems a quick result

Even more rewarding is to see the caterpillar garden hitting its stride – nicely filled out, floriferous already, weed-free and colour-toned as I want it. It has taken about eighteen months to get it to this stage. Gardening with perennials is very different to gardening with trees and shrubs. As long as you have plenty of divisions and the ground is well-prepared, the plants can rocket away and fill spaces quickly.

Species selection of R. sino nuttallii, singled out for its unusual pink flush

However, no perennial can compete with the sheer magnificence and stature of the nuttallii rhododendrons that flower for us at this time of the year. These are not often commercially available – at least not the sino nuttallii species. You may sometimes find some of the hybrids around that are nuttallii crossed with lindleyi, sometimes with the addition of dalhousiae. If you find ‘White Waves’ on offer in New Zealand, it is proving to be one of the best of the hybrids we grow – reliable and a good survivor as well as very showy indeed. “Mi Amor’ is also available for sale. The hybrids have smaller leaves than the nuttallii species and are not all as strongly scented  but you may just have to take what you can find if you want to try growing these choice rhododendrons.

Rhododendron nuttallii x sino nuttallii – so the Tibetan form crossed with the showier Chinese form

 

 

 

The vexing issue of underplanting

A row of alternating annuals makes a statement, though it may not be the statement the gardener is aiming for

I had a day out and about looking at gardens recently and I was struck by the nature of under planting, though this preoccupation may have had more to do with my thoughts at the time. What I noticed about the under planting was how badly it was done in a couple of gardens. Bear with me, dear readers. You are going to have to imagine it because I know the garden owners so I was not going to whip out m’camera and take photos of the worst examples to embarrass them in the newspaper and on line.

Words like mishmash and hodgepodge came to mind as I looked at the bottom layer of plants in otherwise perfectly competent gardens. In other words, they had good upper layers of larger plants but when it came to the bottom layer of ground covers and under plantings, the selection criterion seemed solely that the plant should not reach more than 30cm in height. And there was one of this, one of that and one of the other, bunged in higgledy piggledy in most spaces.

Even worse, and I had to visit my local garden centre to set up a photo to demonstrate, is the horror of alternating annuals in a row along the edge. These certainly make a statement in the garden, though it may not be the statement that the gardener thinks when he or she plants them. I saw something similar (maybe with pansies and alyssum?) looking incongruous in a garden with otherwise high quality woody trees and shrubs and there were not any resident children to justify such a lapse in taste.

Nor am I a fan of edging plants, or indeed anything planted in rows other than proper hedges or vegetables, but that is a matter of style and personal taste. Fringes of mondo grass, liriope or anything else leave me cold but edging rows of matched annuals make me raise my eyebrows. Not even moderately tasteful white petunias cut the mustard when planted as an edging.

The contemporary look is to plant in blocks. The landscaper look is to plant in sharply defined geometric blocks each comprised of only one evergreen plant. Clivias are good, renga renga lilies are a bit untidy. Hellebores are probably acceptable, as is liriope or trachelospermum. Natives like prostrate muehlenbeckia are better.

Bergenia ciliata and Siberian irises – this gardener’s version of block planting

The middle ground is to gently block-plant but in more interesting combinations and in less rigidly defined grids. I am far more comfortable with that approach and it makes gardening interesting to play with different combinations. It also has advantages in making maintenance easier to group plants which require more frequent care – such as dead heading, staking, dividing, or grooming. Rectifying mistakes or bad decisions including eliminating invasive thugs is more localised if you are planting in blocks. I tend to blur the edges of my block plantings so that the overall look is softer and less delineated because that suits our style of gardening better. There is no doubt that if the upper layers of the garden are varied and mixed, some sort of unity in the bottom layer creates a more harmonious picture. I would argue that the flip side of the coin is also true: if your upper layers are rigidly conformist and consist of restrained plantings of only one or two different plants, ringing the changes with more complex and varied under plantings will make it a great deal more interesting.

Acceptable clivias

If you don’t want to go the block planting route, the old fashioned cottage garden genre may be an alternative. Essentially this is a jostle of perennials, annuals and bulbs in combination with small shrubs, often roses, where self seeding is encouraged. If you want a more modern look, you colour tone it rather than the traditional riot of random colour that nature achieves. If you like a tidy garden which is weed free, it is not an easy style to manage well. More often it is best viewed in passing, rather than looking at the detail.

Then, of course, you could ask yourself whether under planting is even necessary in some areas. The requirement that all garden beds and borders be layered with nary a glimpse of garden soil is relatively recent. In times past, it was fine to plant shrubs and trees without any bottom layer at all. It was called a shrubbery. Just don’t plant the shrubs too close together or you end up with a hedge. Each shrub needs to stand in its own space. As nature abhors a vacuum, mulch all the bare earth with something anonymous or you will grow a carpet of weeds. It is certainly easier to maintain than more complex plantings. It will probably look more attractive than the hodge podge assemblage of random plants I saw. It should look classier than the row of alternating annuals. Maybe it is time to start a movement called The Shrubbery Revival. Neo-shrubberies, maybe?

First published in the Waikato Times and reprinted here with their permission.