Flowering this week: Moraea polystachya

Moraea polystachya - blue lilac flowers all autumn into winter

Some bulbs are a fleeting seasonal delight but you can’t say that about Moraea polystachya which has been a sight to behold for many weeks in our rockery and which will continue to flower for some time to come. The wiry stems are about 50cm high and while individual flowers don’t last long, fresh buds keep opening because it flowers down the stem, a bit like a bearded iris. The colour is an intense blue lilac with yellow markings. When the foliage follows, it is narrow and unobtrusive so these are not plants which take up much room.

Moraeas grow from corms, like gladiolus, and most of the family hail, yet again, from South Africa. It is the spring flowering M.villosa which has given the common name of peacock iris to the whole family (its flattish blooms have markings like the eye of a peacock feather). Polystachya looks more akin to a dainty iris. It is not tricky to grow and seeds down easily in well drained conditions without becoming weedy. If you can find somebody with one, it sets seed freely and is easy to raise. I have never timed its flowering season from go to whoa but it is more likely into the months rather than days or weeks.

In the Garden this week: May 14, 2010

Gather up the pumpkins and their relations before the bad weather hits

• No doubt the weather statistics will confirm in due course, but this autumn seems to be notable for the extended spell of calm, sunny, dry weather. It will run out soon and we will be complaining about damp, bleak and cold days so make the most of the mild conditions while they last.
• If you wish to use sprays on your lawn to kill out flat weeds and invasive competitors, it is much safer to surrounding plants to apply in autumn. Most lawn sprays are hormone based and designed to leave the grasses while targeting unwanted plants. Hormone sprays are particularly damaging to vulnerable plants which can be affected by even the slightest of spray drift. Always use on a dead calm day. Deciduous plants coming into growth in spring can get hit very hard by a mere whiff (magnolias and kiwifruit in particular) so applying these sprays in autumn can be an extra safeguard and still effective.
• While on lawns, if you wish to fertilise yours, watch the weather forecast and always apply just as the rain is about to start to avoid burning the grass. Don’t be heavy handed – keep to the recommended application rate. If you use a mulcher mower, you don’t need to feed the lawn to keep it lush and green because you are constantly returning the goodness in the clippings.
• If you have any nut trees and have yet to gather the autumn harvest, the rats will likely be beating you to them. It doesn’t pay to delay picking them up. As a general rule, nuts need to be dried in a warm, airy position for a few weeks before being stored or used. The personal nut favourite here is the enormous walnut we grow (nice and easy to shell) but it is not a heavy cropper.

Each walnut is large but the entire crop this year was not a great deal more than this

• Lift the last of the season’s potato crops to avoid damage from insect pests and blight. Gather up your pumpkins before the weather turns cold and wet. Likewise, keep your compost covered to keep it warm and dry. We use heavy black plastic for this.
• Sow down bare areas of the veg garden in a green crop. Lupins are a good winter option and have the added bonus of fixing nitrogen in the soils.
• If you haven’t renovated your strawberries, get onto it straight away because these are spring croppers and they need to get re-established while conditions are still mild. You can split the clumps if they are a clumping type or replanting the runners and discarding the old crown is the usual method. Replant them in well dug, friable, rich conditions in full sun.
• The early spring bulbs are all coming through the ground. Watch where you put your feet and be cautious with weed spraying and push-hoeing.

Threatened Plants of New Zealand

After last week’s book review lambasting an author who was way out of her depth, the first indication that this publication is in a different league altogether is the use of multiple authors, all with short biographies which demonstrate a depth of experience and knowledge of the topic. You can be sure that this major reference book has been extensively peer reviewed.

It was a revelation here just how many of our native plants are threatened with extinction – one in thirteen apparently. We knew about Pennantia baylisiana (down to a single, naturally occurring plant in its habitat on Three Kings Island) because we have a large cutting-grown specimen from it in our own garden. Similarly we knew that the kakabeak was seriously endangered but not that it too was reduced to a single plant in the wild. Many of the other threatened plants were news to us and the authors are flagging real concerns that we are in danger of losing our diversity of native plants. Alas plants are not as cute as black robins or kakapo so they do not garner the same public attention.

This is a sumptuous hardback book with a great deal of technical information but well organised and presented so that a broad spectrum of interested readers can find the information they need. Each entry has its botanical name, conservation status measured by accepted national and international convention, botanical description, details of how to recognise and identify the plant, its distribution, habitat and threats to survival. Add in several photographs and a map showing the location in the wild and you end up with a really good reference book which will last for many years in this country. Its somewhat hefty price-tag is justified and anybody with an interest in our native flora or botany will want to have their own copy on the bookshelf.

Threatened Plants of New Zealand by Peter de Lange, Peter Heenan, David Norton, Jeremy Rolfe and John Sawyer. (Canterbury University Press; ISBN: 978 1 877257 56 8).

Tried and True – vireya rhododendrons

• Extended flowering, sometimes more than once a year.
• Once established, generally only need dead heading and an occasional prune.
• Available from garden centres in a range of colours.
• Easy to propagate at home from cutting.

The smaller leafed, smaller flowered vireya hybrids are often tougher and better performing as garden plants.

This small flowered yellow vireya has been a picture in full flower in recent weeks. Vireyas can be touchy as garden plants but get them well established in a frost free area with good drainage and they are most rewarding. Unfortunately people are often drawn to the exceptionally showy, fragrant varieties and bypass these less spectacular types. The big scented trumpet types with heavy felted foliage can be very touchy indeed and you often don’t get the flower power display of the smaller leafed, smaller flowered ones. This particular one is a sister seedling to one we have sold in the past under the name of Mellow Yellow but there is a whole range of different vireyas available with the same characteristics – in different colours too. They are hardier and tougher by nature and certainly justify a place in the garden. Flowering times are unpredictable with vireyas but many will repeat flower later in the year or gently open flower buds over an extended period of many months.

Pruning a rampant climber: step-by-step with Abbie and Mark Jury

1) This climber has gone well past the point where a light trim will suffice and allow more light in the window behind. However, we don’t want to dig it out and cutting it off at the ground is likely to kill it. This is an ornamental jasmine (not the dangerously rampant variety) and we like the fragrance.

2)The tendrils going over and under the spouting, and even worse, under the roof tiles are a warning that action needs to be taken now. Looking into the mass of vines, you can see that the downpipe is under threat and also that the plant is putting out new growth from the middle and not just on top.

3) Cut back the foliage hard. We are aiming for a curved shape around the corner of the house. It is easier to work out which vines to keep when you can see where each one is headed. You can use a chainsaw for the initial shaping and follow up with clippers and secateurs to tidy up the rough cuts.

4) Trace the path taken by the vines and remove unwanted stems in sections. If you try and pull it out in long lengths, you run the risk of damaging the growths you want to keep. We are trying to protect the house and to allow the window to be opened so we are thinning extensively. More frequent pruning would have avoided this.

5) Thin out clutter and remove all dead wood.

6) The finished product looks shorn and a shadow of its former self but should grow away strongly. In our mild and soft climate, we can do this type of cutting any time of the year but gardeners in cold, inland areas may wish to wait until late winter or early spring, timed for just before the plant will put on its first flush of new season’s growth.

7) This is the photo that we did not use in the newspaper when this feature first ran – not perhaps the best advertisement for safe practice (though Mark asserts that he was holding on tightly with the hand which is out of sight…).