May 18 2007 In The Garden This Week

  • If you have a patch of helleborus orientalis (commonly known as winter roses), you may like to go through and cut all the old leaves off at this time. This allows the charming new flowers to be more visible as they otherwise tend to hide below the foliage. It is a good time to mulch around the hellebores.
  • Hellebores are one clumping perennial which does not like to be dug up and divided. They are frequently grown from seed and not division. The seedlings come up very readily in the garden but it pays to weed them out while they are still small or you risk the plants getting overcrowded. They don’t come true from seed unless you have isolated the mother plant and hand pollinated it. So to increase the double flowered varieties or the exciting new slate coloured ones, you will have to divide it but be patient because it can take several years for the plantlets to recover and perform well.
  • Polyanthus, however, do respond well to being divided. Indeed if you look at a plant which you may have bought as one substantial clump some time ago, you may notice that there are now multiple small plants and no large one. If you lift the small plants and give them space to grow, they will reward you with renewed vigour and flowering.
  • Sasanqua camellias are in flower now if you looking for late autumn colour.
  • Clean up established lawns by getting rid of broad leafed weeds, hydrocotle and oxalis. There are specific sprays which will target these weeds and it is safer to surrounding plants to spray now rather than waiting for spring. Sulphate of ammonia can also be used to suppress broad leafed weeds.
  • Harvest feijoas. They don’t last long if you leave them on the ground but will keep better in cool conditions.
  • Plant out strawberry runners for spring crop. You can divide established crowns if the plants are not producing runners, which some modern varieties don’t.
  • If you have not yet given your citrus trees a copper spray, then get on to it. It is the most important spray of the year for citrus.
  • Clean up asparagus beds. You can lightly fork the surface to counteract compacting and caking of the soil but be careful not to damage the crowns of the asparagus. Mulching will keep the bed looking tidy and suppress weeds as well as enriching the soil.

A drift of bluebells, not a mass planting

When is a mass planting not a mass planting? When it is a drift, of course. I recall writing a few weeks ago that we did not go in for mass plantings here (such a sweeping statement on my part) so when The Husband spent several days last week planting out his bluebells, I had to think about why it never occurred to me that these might be a massed planting.

The bluebell planting was a bit of triumph for Mark. He had been gently nurturing a patch in the vegetable garden to build numbers and came up with about 2000 this year. Now 2000 bluebells may sound a large amount to most people but his mission, he explained, was to try and get that 2000 to look more like 20 000. It takes a huge number to have much impact in a large area.

Readers who have been to England in the springtime may have seen the bluebell woods in flower. It is a genuinely charming sight. English woodlands tend to be very open, spindly even at times and deciduous, allowing sufficient light for these unfussy bulbs to spring up and flower just at the point when the trees are about to break into leaf. Where the woodlands contain many of the native white trunked birches, the effect is even more delightful.

With our heavy use of evergreen trees and shrubs in this county, finding suitable spots for bluebell drifts is more problematic and Mark would tell you that it took him longer to decide where to place his bulbs than to actually plant them. They need reasonable light levels but also areas where the grass growth is not so strong that it will choke them out. And they needed to be on the margins where we weedeat, rather than the grassy areas where we mow.

We had thought that the common English and Spanish bluebells belonged to the scilla family but “Bulbs for New Zealand Gardens” by Terry Hatch and Jack Hobbs tells us that they have been moved out of the scilla family and are now members of the hyacinth family (hyacinthoides for those of you who may want to know). This moving of plants through botanical families is based on scientific research but can be trying for gardeners who don’t always keep up with reclassifications. Just keep thinking of them as bluebells, maybe. Non-scripta is the English bluebell, hispanica the stronger growing Spanish form but they cross freely so many of us will have ones which are in fact Spanglish hybrids.

The difference, I figured, between a mass planting and a drift is that the latter is designed to complement other plants already present and to create a natural look of self sown plants drifting through an area. A mass planting is a mass – filling an area by block planting in a single plant selection or a very limited range of plants.

It is not that long ago (a decade or so) that mass planting was pretty well unheard of in a domestic garden. Sure there have always been avenues of matched trees (Tupare’s cherry walk, for example) or hedges comprised of a single plant variety but the idea of filling a garden with a very restrained plant palette was not the common practice it is now. It is probably true to say that the value was instead placed on having as wide a range of different plants as possible. Bulk or mass plantings tended to be confined to the public domain of parks. The transition in the home garden came first with the idea that plants should be in groups of uneven numbers but that rarely exceeded groups of three or possibly five in larger gardens. I don’t know where this edict originated but it certainly caught on. And I can see why. It takes a high level of skill to put together a very wide range of plants and to achieve an effect which is pleasing to the eye, as opposed to messy or random. Starting with plants in groups is more likely to give a sense of order which appeals to many people. A block of three white rhododendrons with five red camellias, under planted with an attractive green hosta and surrounded by tidy box hedging is going to look effective from the start, even in the hands of a novice gardener. No matter that the camellias will almost certainly not flower at the same time as the rhododendrons. It is a great deal more difficult to put together a collection of forty different plants well.

In a discussion on the merits or otherwise of mass plantings, Mark recalled hearing the Queen’s head gardener speak a number of years ago. On the huge royal estates, there was a certain amount of call for some massed plantings but John Bond said that rather than a bed of massed red rhododendrons of all the same variety, he much preferred the idea of raising seedlings from a selected species or hybrid and planting those. The sister seedlings will give subtle variations without being discordant and he felt was of much more interest than identical plants. Alas you have to be able to raise your own plants to achieve this effect. It is not as if you can go and buy sister seedlings off the shelf at your local garden centre. But as a compromise position, it has a great deal of appeal.

I have promoted the gardening programmes on the Living Channel before but at the moment there is a most interesting young(ish) English landscaper with two series running. On “Urban Outsiders” you can see Matt James working on small urban wastelands in USA – mostly New York and Los Angeles – and by wastelands, I mean the most unappealing and inauspicious back yards. In “The City Gardener”, he does the same on tiny English yards. These are more than the usual garden makeovers and even those of us who measure our gardens in acres rather than 30 square metres can learn a great deal. He is very good at what he does. His designs are individual, creative and practical and closely tailored to the needs of the client. He is passionate about good design, about different plants and about inspiring the clients to take ownership of their new gardens by involving them in the execution of the design. This is not “do it for me” gardening. It is “do it together” and Matt gives out a great deal of information in the process.

Interestingly, even working hard to give some cohesion to small spaces which are owned by people with no background in gardening at all, there is no evidence of mass plantings or a heavy use of utility plants or formulaic combinations. He works hard to chose appropriate easy care plants but with variety and seasonal interest. He is worth watching to see a practitioner who brings together excellent design, plantsmanship and an engaging enthusiasm.

This week May 11 2007

If you are planning to move any large plants this winter, do not delay on starting to wrench them. Make a deep cut around two sides of the plant allowing for as large a root ball as practical. In a month’s time you make the remainder of the cuts and then lever the plant out a couple of weeks later. This slow preparation greatly reduces the shock to the plant and increases the chance of moving it successfully. It is particularly important to go through the wrenching process for large evergreen plants.

  • It is a myth from England that you can not move magnolias successfully. This may be true in the UK but we can vouch for the fact that it is possible to move quite large magnolias in winter without even wrenching them, as long as you take a large enough mass of roots with them.
  • Dig and divide. It is a very satisfying way of getting plants for nothing. But discard any plants which indicate that they are spreading alarmingly fast and threatening a takeover bid. And beware of the feeling that you must use all the plant divisions no matter what. There are limits to how many achillea, for example, that any garden needs. The compost heap is fine for surplus.
  • Spray citrus trees with copper. This is a very important spray to reduce diseases in the spring. Copper combats brownspot on the leaf and fruit which rots on the tree before it ripens. Mandarins are particularly susceptible.
  • Now is traditionally the time for a main sowing of broad beans. You can still continue planting brassica plants. Harvest pumpkins before they go rotten and dig main crop potatoes.
  • The autumn clean up in the vegetable garden is an important part of keeping pesky diseases at bay and good tidy practices will reduce the need for spraying in the future. The same is true in rose gardens where diseased foliage is best removed from the garden bed. The advice is generally not to compost rose leaves unless you manage a mix which heats up enough to kill the fungi and bacteria. If your compost does not get hot enough, you risk circulating weed seeds and every undesirable problem when you spread the compost around the garden later.

This week May 5 2007

  • If your hostas are looking distinctly unwell, it is because they are going dormant for winter. All their leaves will rot off and the plant hibernates below ground. If you have well established clumps, you can lift and divide them any time from now on until spring.
  • Lifting and dividing is the gardening term used to describe the process of splitting up clumping plants (as opposed to woody trees and shrubs). These include perennials such as hostas, grasses, flaxes and asters. These types of plants can get very congested if you just leave them whereas they will gain new vigour if you divide up the clump. To get maximum small plants, wash the roots (so you can see what you are doing) and then split into divisions so that each piece has some roots and a few growing tips. Cutting a clump into sections with a spade or sharp knife is less precise but will work just fine. Replanting the divisions into well cultivated soil gives the plant a good start again.
  • If you don’t want to lift and divide, gouging out some of the central growing tips will reduce congestion, as will scratching around the outside perimeter of the plant and chipping away some of the bulk.
  • Winter is approaching so in the vegetable garden it is all about battening down the hatches – clearing old crops and either sowing in a green crop or planting winter veg such as spinach, carrots and brassicas. Broad beans can be sown now and even garlic can be planted, if you are keen. It is not compulsory to wait for the shortest day to plant garlic.
  • Keep spraying with copper to beat fungal diseases. Copper is regarded as a safe chemical to use on edible crops with a very short with holding period before it is safe to eat them.
  • If you have a very sheltered and favoured spot, you can do a planting of early potatoes. Use a quick maturing variety such as Jersey Bennes or Rocket and you may be able to compete with the highly priced first crop new potatoes which appear in the supermarkets at the end of winter.

This week April 27 2007

  • A couple of weeks ago we talked about the autumn rains having arrived. Well they have been and gone so watch out for container plants drying out too much and maybe hold back on too much planting or shifting of trees and shrubs until the rains return (which they will, this being Taranaki not Australia).
  • Dry spring bulbs can still be planted although it now too late to lift existing bulbs and divide them.
  • Don’t delay on sowing new lawns and April is good month for topdressing. Time it for just before rain or the sun may act with the fertiliser to burn the grass. If the nitrogen doesn’t get washed in, much of it will disappear in the air. Use a cheap NPK fertiliser, or Bioboost works well.
  • If you covet sweet peas, sow them now in a well dug bed with lots of rich compost. They need a frame to climb up and are ideal for growing in the vegetable garden as a cut flower.
  • Sow leafy greens now from seed. The female half of our household regards silver beet as stock food but others may like to plant it, especially the coloured chards which are allegedly ornamental. The same goes for swedes, kohlabi and turnips which can be planted now if you are desperate enough to want to eat them later.
  • Rhubarb (which we do like upon occasion – very nice cooked the Alison Holst method with sago) can be divided and planted. It likes plenty of compost and fertiliser.
  • Plant strawberries. If you have runners from the season just past, you can use these but some of the newer varieties do not seem to put out runners. In our climate, strawberries are often treated as an annual and tend to give their best crop in the first year.
  • Take cuttings of fuchsias, lavenders, pelargoniums and similar plants now. Apparently you can use honey instead of rooting hormone – presumably liquified honey but we have never tried it.