Tag Archives: gardening

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.

Garden lore

I am strongly of the opinion that a quantity of plants, however good the plants may be themselves and however ample their number, does not make a garden; it only makes a collection.

Colour in the Flower Garden by Gertrude Jekyll (1908).

Dead heading

Plants don’t flower to delight humans. That is merely a bonus for us. Plants are genetically programmed to reproduce themselves and flowering is part of that process. Dead heading plants is therefore akin to contraception – preventing them from setting seed. In many cases, the plant will try again and set more flowers. That is what happens with annuals, perennials and repeat flowering roses. Removing spent blooms will extend their flowering season considerably. It doesn’t work for plants where flowering is set the preceding year (bulbs, rhododendrons and many other woody plants) but interrupting the process of setting seed can make the plant concentrate its energies on fresh growth and setting more flower buds instead. Annuals and biennials die after setting seed. Some plants can set so much seed that they weaken themselves and may eventually die (some rhododendrons and pieris, for example). Plants which are sterile often flower extremely well because they never get past that optimistic first stage of procreation.

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

Plant Collector: Gesneria cardinalis

Gesneria cardinalis, or maybe Sinningia cardinalis

Gesneria cardinalis, or maybe Sinningia cardinalis

The tuber in growth. I have cut chunks from it to grow new plants.

The tuber in growth. I have cut chunks from it to grow new plants.

Gesneria or sinningia? We have always known it as a gesneria but it appears that Sinningia cardinalis is equally valid as a name. Whatever, this is a comparatively rare plant which comes from the same family as both African violets and gloxinias – the family having the near unpronounceable name of Gesneriaceae. Most hail from South America and cardinalis is from Brazil.

Unlike most members of the family (and there are somewhere over 40 of them), cardinalis grows from a tuber which pushes itself above the ground. We have described it in the past as developing a football-like tuber, but with the passage of time, ours are getting closer to exercise ball in size. The leaves are soft and somewhat hairy while the tubular red bells sit above the foliage and flower over a long season in late spring. Come autumn, all the leaves will fall off. This is a plant for dry shade but needs to be frost free.

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

Garden lore

Garden radishes are in wantoness by the gentry eaten as a sallad, but they breed but scurvy humours in the stomach, and corrupt the blood, and then send for a physician as fast as you can.

The Compleat Herbal by Nicholas Culpeper (1653).

Spring planting – NOW

If you have not planted out your summer garden, now is the time to panic. An unseasonably cool spring may have led many to delay, but delay no longer because the official start of summer is a mere two weeks away. Top priority needs to be given to the plants which require the longest growing season. This includes capsicums, aubergines, both rock and water melons, kumara and even tomatoes. Starting with plants now, rather than seed, is advisable to get a jump start this late in the season. Other techniques are to plant in black plastic (which heats up the soil faster) and to use a cloche for the early stages because this heats up the air around the plant to encourage growth.

The late spring bulbs


Left to right: Gladious carneus, a dainty allium, Romulea rosea, camassia, Phaedranassa cinerea, Stenomesson miniatum, Gesneria cardinalis, calanthe orchid, Albuca candadensis and spiloxene.

When spring bulbs are mentioned, most people think of daffodils, bluebells and tulips. But when they have been and gone and all that is left is the scruffy foliage, there are the late spring bulbs coming into flower. Most of these are less well known and certainly less celebrated in literature and art. For all that, they are often more interesting, maybe because they are unexpected.

We love bulbs here and with bulbs I include corms, rhizomes and tubers. More than any other type of plant, they seem to mark the passage of the seasons and to create the smaller, detailed pictures that add layers of interest to the garden. Maybe because the perennials and annuals are coming into their own at this time, the late spring bulbs are often ignored and therefore harder to source.

I headed out to the garden to see what was coming into flower. Discounting the earlier bulbs which are still flowering but well past their peak (veltheimias, the late lachenalias, Hippeastrum aulicum and the like), I found about 20 different types of bulbs coming into their own and that is by no means complete. There is little which is duller than endless lists and plant descriptions so I lined a number up for photographs.


Clockwise from top – Soloman Seal (Polygonatum multiflorum), tritonia, babiana, Satyrium odorum (orchid), rhodohypoxis, Watsonia brevifolia, tulbaghias – probably comminsii and possibly simmleri

I featured the rhodohypoxis in Plant Collector a fortnight ago. These are relatively common and form attractive carpets in pinks, whites and carmine red with their mass of star flowers. There is nothing rare or exclusive about Soloman Seal (Polygonatum multiflorum) either. It was common in the gardens of grandparents and is perhaps undergoing a surge of discovery amongst newer generations of gardeners. It is particularly handy for semi shade positions and, after battling a near impenetrable mass of entangled rhizomes, I decided it may well have some merit as a natural stabiliser for an eroding bank. I will report back in three years about the success or otherwise of this venture but as it will grow pretty much on top of the ground and grip hard, I am optimistic. As a bonus, the foliage turns golden in autumn – an unexpected source of autumn colour for us.

Hippeastrum papilio

Hippeastrum papilio

For sheer exotica, it is hard to beat Hippeastrum papilio which is just opening. Papilio means butterfly though I think it is more orchid-like really. This is a spectacular bulb from Brazil which is offered for sale from time to time. It is more expensive than rare. We had to try a couple of different places in the garden before we found a spot where it was happy but we now have it thriving in open woodland conditions.

Scadoxus puniceus

Scadoxus puniceus

While on the big bulbs, Scadoxus puniceusis one of our showiest but I won’t dwell too long on it because it is rather too frost tender for inland areas and rare in this country. Its cousin, Scadoxus katherinae, is a better bet for frosty areas because it is dormant in winter and doesn’t start moving until spring, flowering in summer. Similarly, our love affair with the arisaema family (sometimes called snake’s head lilies though they aren’t lilies) is of limited value because our showiest ones are Mark’s hybrids which we have never sold so they can’t be seen anywhere but in our garden. Given time, we may put them on the market but that is a way off. Most of the arisaema family hide their flowers below the foliage but Mark has managed to breed with varieties to bring out the desirable trait of holding their flowers above the leaves, making them much showier as well as being easy garden plants. You may, however, find Arisaema speciosum which is easy to grow and Arisaema ringens is relatively common. If you have a bank that you look up to, the flowers are little more obvious without having to part the leaves to see them. We describe A. speciosum as the closest thing to a cobra you would want in the garden.

If you are getting frustrated trying to find more unusual plants, there are good reasons why. Many if not most of the specialist nurseries throughout the country have closed down over the last decade as have most mail order nurseries. Treasure the ones that are left because there are few new plant businesses opening. However, bulbs are perhaps a little easier than trees and shrubs and I occasionally look at the bulbs section of Trade Me and see some interesting and less common material offered for sale there. Beyond that, you may have to start haunting your local horticultural society or keen gardening groups where there are likely to be one or two people who know their bulbs from their onions.

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