Tag Archives: gardening

Plant Collector: blandfordia (February bells here)

Blandfordia - Australia's Christmas bells

Blandfordia – Australia’s Christmas bells

Christmas bells is the common name. Apparently in their homelands of Australia, these bulbs flower around Christmas. They are somewhat later here but the flowering lasts many weeks. It is not that there are large quantities of blooms, just that they come in succession and each trumpet lasts for a long time. These ones are on stems about 30cm high. The foliage is small, anonymous and grass-like at the base.

There are four different species of blandfordia and they have been given a family all of their own. They are hugely variable in colour and flower size, ranging from all red to all yellow, which makes identification difficult. We think this one is most likely to be Blandfordia grandiflora (so-named because it has the largest flowers) which is native to New South Wales and Queensland. There is a slight hesitation, however, between that and the Tasmanian form B. punicea. Unless an Australian botanist arrives at the right time, we may not get a definitive identification.

You don’t see blandfordias around often, or used in cut flower production, because they are slow to establish. Really slow, in fact. The references say up to 7 years to get to flowering size. In our case, maybe add another 7 before we started getting consistent flowering. Ours appears to be largely evergreen, keeping some foliage year round. Blandfordias need excellent drainage but not dry and baked in arid conditions.

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

The Chelsea chop comes to New Zealand

Lobelia, phlox, campanula, aster, pensetemon and coreopsis - all candidates for the Chelsea chop here

Lobelia, phlox, campanula, aster, pensetemon and coreopsis – all candidates for the Chelsea chop here

We are fairly dedicated viewers of the long-running series BBC Gardener’s World. Of late it has been on free to air Choice TV (interspersed with huge quantities of advertising) and sometimes it turns up on the Living Channel. There was a programme that screened here last November which demonstrated the technique of the Chelsea chop. I tried it in a small way and will be doing a great deal more of it this coming year.

The Chelsea chop came by its name, apparently, because at the end of the annual Chelsea Flower Show, many surplus plants were returned to nurseries. These plants in full growth, nearing or at their peak, were often cut back hard. Presumably some were plants forced into early growth to peak for the show and that early growth can be leggy. Plants responded with greatly increased vigour and put on extended floral displays with much bushier and more compact shapes.

Thus did the term the Chelsea chop enter the lexicon of English gardening.

Right, I thought. Chelsea is towards the end of May which translates to November in our hemisphere. I headed out with the snips to experiment. It seemed extreme because I was cutting off flower stems which were already well advanced. In some cases, I cut half and left half. I can now report that it works and I will be doing a great deal more of it next spring.

Important points to note are that we are talking about perennials here, not shrubs or bulbs. You need to understand your perennials because it only works on varieties which repeat flower. If you snip the ones which only flower once, such as irises or aquilegias, you won’t get any flowers at all.

I tried it on perennial lobelias, sedums, penstemons and asters.

The unchopped lobelias have shot up their flower spikes to over 1.5 metres and they have promptly fallen over in the welcome rain this week. The plants I Chelsea chopped are only a few days behind in their stage of flowering but have tidy, sturdy stems about 50cm high. They are much better in the garden borders.

Sedum, left to its own devices and falling apart already

Sedum, left to its own devices and falling apart already

Many readers will understand when I complain about the sedums which grow brilliantly from such tidy rosettes at ground level but when they reach a certain point of being top heavy, they fall apart. The Chelsea chopped ones are a more compact and holding together at this stage.

I cut the asters because I didn’t want them to flower until late summer and they were threatening to do it too early. They are just opening now, on lovely bushy mounds of plant, and should take us into autumn.

I see the Telegraph website advice is to do it with Campanula lactiflora (which can get a bit too tall and fall over if you don’t stake it), rudbeckias, echinaceas and heleniums as well. Their writer advises to prune back by a third. Essentially it is a more extreme version of pinching out plants at their early stages to encourage bushier growth.

Perennial gardening is our current learning project here. We have been working on it for a few years now and the more we learn, the more we realise there is to learn. New Zealanders don’t have a great record in perennial or herbaceous gardening. We lean more to bunging them all in together in mixed borders, or working from a very limited palette in large swathes of the same plant.

Sedum, cut back last November and holding itself well. Flowering is unaffected

Sedum, cut back last November and holding itself well. Flowering is unaffected

The mix and match approach to perennials is very English. They just do it so much better than anywhere else we have seen. Underpinning it (at its best) is a wealth of experience in successional flowering and good combinations. It is not just flower colour combinations, it is also compatible growth habits. This may be growing a naturally leggy plant (such as Campanula lactiflora) through a plant that is sturdy enough to support its leaning companion. It is making sure that a big voluptuous plant can’t flop all over a low growing, more retiring specimen. It is getting variations within the foliage as well as the flowers. It is getting the plant shapes right.

And it is not just peak flowering looking its best for three weeks of the year. It is understanding which combinations will take the garden through the season from spring to autumn, so as one finishes, another star takes centre stage. Judicious use of the Chelsea chop can extend the display, staggering flowering through the season.

There is a lot to it. No wonder people opt for mass plantings of the same plant. It is much easier. So too with the cottage garden which does not require the same level of skill. This type of intensive gardening is not to everybody’s taste but we are finding it interesting to learn. To be honest, I had not appreciated the skill that goes into putting in a really good planting of herbaceous material.

I will be doing my best impersonation of a garden hairdresser come this November. I will be out there snip, snip, snippin’ away.

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

Plant collector: Jacaranda mimosifolia

The summer delight of the jacaranda

The summer delight of the jacaranda

South Africans could be forgiven for thinking that this tree is one of their indigenous species. Pretoria has so many planted that it is apparently a haze of blue in late spring to early summer. In fact it comes from Bolivia and Argentina but is a worldwide hit because blue flowered trees are not common at all when you think about it. Nearer to home, when we last visited Whakatane, they too had used this summer flowering delight as a street tree. But it is nowhere near as common where winters are wet or in inland areas because it is a subtropical plant. Our tree is growing in a protected position, surrounded by other trees, rather than standing in solitary splendour so its blue-as-blue floral display is best seen out of our upstairs windows.

Jacarandas are deciduous and make an airy, open tree. After many years ours has reached around nine metres high, though it will have been stretched up by the trees around it. The flowering season lasts many weeks but it does appear that cooler temperatures delay the season until mid summer. In less than ideal conditions, it will need a sheltered, favoured position with excellent drainage in the warmest possible situation. It is classified as a member of the Bignoniaceae family though most gardeners will just recognise it as a legume.

Garden lore

“The gardener has a great faith in names; a flower without a name, to put it platonically, is a flower without a metaphysical idea; in short, it has not a right and absolute reality. A flower without a name is a weed.”

The Gardener’s Year
 by Karel Čapek (d. 1938)

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Summer grapes

Grapes are not a fruiting vine that can be left to their own devices if you want a harvest. They need hard pruning in winter and a follow up in summer. If you haven’t yet summer pruned your grape, then get onto it immediately. Cut all the laterals (side growths) back to six leaves. This allows light to reach the bunches of fruit and concentrates the plant’s energies on ripening the fruit rather than supporting extra foliage.

At the first signs of the fruit ripening, get bird netting on. Our feathered friends rarely wait for fruit to ripen to the stage humans prefer. If you can keep the birds from pecking the fruit, it will reduce their attractiveness to wasps.

By far the most successful, outdoor grape variety we have found in our marginal conditions is Albany Surprise. It is an American hybrid and should grow well in areas which are not known for grape growing because of humidity, rainfall and mild temperatures.

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

The answer, as they say, lies in the soil

What is visible above ground is entirely dependent on what is happening below

What is visible above ground is entirely dependent on what is happening below

A reader took me to task for last week’s column, objecting to my careless use of dirt as a synonym for soil. I would argue that “dirt” is merely the vernacular and in no way demeans the gravitas of soil, but it did get me thinking about the natural growing medium beneath our feet. I also found a wonderful throwaway comment in the same book that gave this week’s gardening quote – The Curious Gardener’s Almanac.

Following on from the old adage of “look after the soil and the soil will look after the plants” was a variation on the theme: “Feed the soil, not the plants”. Yes, I thought. That was a message that spoke to me. We swim against the modern tide and rarely use garden fertiliser here, preferring instead to rely on home-made compost.

Garden soil must be the least sexy and interesting part of gardening for the novice. Yet every single experienced gardener, without exception, will tell you that the state of your garden soil is critical to the end result with the plants. It is just that the plants are a lot more interesting so beginner gardeners start with them. There can be an awful lot of fatalities before they work out that the state of the soil may need some serious attention.

The current craze for no-dig gardening is another issue altogether which I may return to in the future. But whether you opt to plant in the ground or on top of the ground, the growing medium that houses the roots of all your plants is critical.

We are in-ground gardeners here and are lucky to be on free draining, fine, volcanic loam which is one of the easiest natural mediums of all with which to work. Others are nowhere near as lucky.

The aim is to develop friable loam

The aim is to develop friable loam

At the ends of the spectrum are the fine, sandy soils (predominantly in coastal areas) and heavy clay. The former is lacking in humus and does not retain moisture or nutrition. The latter holds too much moisture in wet times but can take on a concrete-like consistency in dry times. Clay lacks aeration, making it difficult for plant roots to function well.

Often new housing subdivisions end up with deeply inhospitable soils. In the past, developers were renowned for removing the top soil and then selling it back later when the home owner wanted to start a garden. I have no idea if that is true but where excavation has been necessary, developers are unlikely to understand the need to set the top soil layer aside in order to replace it in its rightful place on top when the site is finally levelled again. They are more likely to mix it all up so you end up with the sub stratas (often heavy clay) dominating the top layers.

If you are new to gardening and are not at all sure what your soil is like, take up walking around your neighbourhood. If you have neighbours, you are sure to find one out in their garden and most will be glad to give you advice. Soil types can vary widely, though if you are in dairying territory, you are likely to have better soils.

If your soils are less than ideal, set aside the prepackaged or processed fertilisers. They are a short term fix for short term plants but won’t do anything at all for your soil structure.

Sandy soils which dry out very quickly lack humus and sustenance for plants. There are probably very few worms, yet these wrigglers play an important role in mixing up and aerating the soil. You can alter the structure, but it takes work and time. You need to load in the compost, leaf litter, grass clippings, seaweed and any other natural material which will add substance to the soil. Keep at it over time too. It is not a one-off task.

Animal manures should be left to age before you bury them in the soil. They are too strong when they are fresh and can burn plants. You can dig a trench and bury your kitchen scraps directly in to the ground. You are just trying to get as much organic material into the soil and then the worms will start arriving along with all the other natural microbial action and insect life of healthy soils.

Clay soils also suffer from a lack of worms but they are not lacking in nutrients as a rule. Basically, the aim is to break up the clay to allow for better drainage, increased worm activity and aeration. Adding gypsum is one strategy. Bringing in very fine gravel or sharp river sand is reputed to help but you are likely to need several centimetres of it to make any difference and it will need to be dug through the clay. Otherwise, do the same as for sandy soils and bring in mountains of humus. Build up your layers on top. The worms will arrive and start to do some of the work for you.

You are trying to speed up a natural process where top soil builds up closest to the surface, giving you friable and fertile conditions in which to grow plants.

None of this is rocket science. It just takes time, effort and a strong back if you are starting with impoverished soil conditions. You often have to take the longer term view in gardening.

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