Tag Archives: gardening

Agapanthus -the blue (and white) stars of our summer roadsides

Our summer roadsides would be the poorer without agapanthus

Our summer roadsides would be the poorer without agapanthus

We have a bit of a love-hate relationship with agapanthus here in Taranaki and in warmer areas of this country. But as you drive around the countryside at this time of the year, most would agree that our roadsides would be the poorer if they were gone. They resemble giant blue harebells growing, well, growing pretty well everywhere if we are honest.

Agapanthus all come from South Africa and from relatively limited areas of that country. Don’t be misled by the common international name, the Lily of the Nile. They are neither a member of the lily family, nor do they grow anywhere near the Nile. Nor does Agapanthus orientalis come from the Orient. That descriptor merely means eastern, so the natural habitat of A. orientalis (probably more correctly known as A. praecox ssp orientalis) should be on the eastern side of South Africa, assuming the original plant collections and recording was done accurately.

The name comes from Greek. Agape is love and anthos is flower but whether this means the flower of love or lovely flower is unclear.

So are they a weed? These matters are rarely as black and white as they appear. On the debit side:
• Most agapanthus set seed freely and the seed germinates readily.
• Agapanthus grow well in a wide range of situations including inhospitable clay banks and shaded areas. They form a dense cover which prevents other plants from germinating – particularly desirable native regeneration. They have the potential to colonise bush reserves, national parks and native bush.
• The common agapanthus are resistant to the world’s handiest weedkiller, glyphosate (formerly known by its original brand name: Round Up). While you can take them out with stronger brush killer sprays, most of these require you to hold a spray licence.
• Digging out well established clumps takes quite some physical strength and determination because the plants cling on for grim death and the clumps can be formidable. Because they have roots which are rhizomes, if you don’t get the whole plant out, what is left behind in the soil will re-grow.
• There is no way this plant would ever be permitted into the country now. Mind you, the same thing could be said about kiwifruit.

There is a credit side and a degree of resigned acceptance by the authorities in this country which sees agapanthus treated as a surveillance pest plant rather than the hard line decision to ban it outright.
• While it seeds freely, the seeds are not dispersed by birds at all so in most cases, the seedlings pop up close to the parent plants. The big problem comes with plants beside waterways because the water can do a very efficient job of spreading them much further.
• They are a significant plant for cut flower producers and there are dwarf and sterile forms available for home gardeners which pose no threat at all. There is a large international market and agapanthus occupy an established niche in our nursery industry. Many of the named hybrids have parentage which includes one or more of the species other than praecox and this reduces the weed problems.
• They make a significant contribution to our summer landscape as a flowering plant and will tolerate harsh, roadside conditions so are favoured for amenity plantings.
• They are evergreen, tidy and suitable for using to stabilise slip-prone areas.

Basically Biosecurity and most northern regional councils would love to ban it outright but pragmatism triumphs so the aggie lives on to flower another day. Auckland has banned the larger growing forms of A.praecox (the common form), still allowing the production and sale of dwarf forms as a compromise position. The sensible position for the home gardener who lives adjacent to native forest or to waterways, would be to remove them entirely. As a back-up position, being industrious and thorough about dead heading would reduce the problem. For the rest of us, it probably doesn’t matter and they make a huge contribution to our summer gardens and landscape.

Agapanthus Tinkerbell - no weed potential here

Agapanthus Tinkerbell - no weed potential here

By no means are all agapanthus thugs. Little Tinkerbell is common in gardens though probably more noted for its very clean white and sage green variegated foliage than its flowers. It is distinctly shy on flowering, as a rule. It also has a significantly large root system for a plant without a great deal on top but it is a useful addition in the garden border. Other named hybrids are often more amenable than thuggish and have their place in the garden setting.

This is a plant family which is a great deal more highly prized overseas than here. In harsher climates, stronger growing plants are valued for their ability to survive the conditions and most of Europe and the US have much harder conditions than we have. Toughies that stay in leaf as well as put on a lovely summer flowering display are harder to come by, especially in blue. Because they don’t tolerate extremely cold conditions, additional measures are often required to get the common agapanthus through winter.

But in this country, you can’t even give away common agapanthus. Which is why we were genuinely shocked by a section in “A Green Granny’s Garden”, by Fionna Hill. I reviewed this before Christmas and I have to admit I did not read it cover to cover or that review might have been a little tougher had I come across the following paragraph referencing her attendance at a Hollard Gardens’ workshop here in Taranaki:
“Workshop participants have been invited to bring seed and other plant material to share. We pulled lots of agapanthus plants from Maggie’s New Plymouth garden that day and (we thought) cheekily we’d take the opportunity to leave a wheelbarrowful. We give the barrow to some helpful children to wheel back to the meeting shed, while we speed off down the road. I think it might not have been welcome, at that time, believing them to be a pest.” (sic). The page of self justification that follows does not mitigate the action for anybody except the author, who concludes: “I shouldn’t feel so guilty about that wheelbarrowful that Maggie and I have left as a contribution – at UK rates, the barrowful was worth about 300 pounds.” I don’t think so, dear. What you did was to furtively leave your friend’s weeds for Hollards’ staff to dispose of. You should be feeling guilty and embarrassed.

Tikorangi Notes: Friday 28 January, 2010

LATEST POSTS: Friday 28 January

1) Agapanthus – love them or hate them, they are stars of our summer roadsides. Abbie’s column.

2) An exceptionally fierce summer storm last Sunday took out many flowers in the garden but the disa orchids came through unscathed. Plant Collector.

3) Garden tasks for the week from dealing with potato blight to why you may want to think twice before planning to become self sufficient in pine nuts.

Agapanthus blue and white, and montbretia on our roadside

Agapanthus blue and white, and montbretia on our roadside

TIKORANGI NOTES:
Agapanthus or Nile lilies are considerably more highly prized overseas than in New Zealand. Here we tend to see them as indestructible, utility roadside plants or fillers but come summertime, these large clumps of strappy foliage are adorned with a mass of blue or white blooms. They become a real feature of our countryside. But such is the antipathy to these plants, that they are frequently looked down on as garden plants. I think the only one we have in a garden situation (as opposed to our road verges bounding the property) is little variegated Tinkerbell.

Variegated agapanthus - doubly damned in NZ

Variegated agapanthus - doubly damned in NZ

I will have to find a spot for the yellow variegated form shown here, but am not sure yet where it will fit. We have never done anything with this seedling of ours. There is no point in building it up for sale in this country – it is damned on account of being an agapanthus, doubly damned because it is variegated in a country where we do not favour variegated foliage much at all, though it is a good plant with stable colour. The crocosmia (commonly referred to as montbretia) is similarly a borderline weed but it lights up the roadside outside with the agapanthus.

Plant Collector: disa orchids

Working to naturalise disa orchids by our stream

Working to naturalise disa orchids by our stream

It was a bit of a mission earlier this week to find anything looking good after Sunday night’s fierce storm but the disa orchids held up well. Trying to get these delights naturalised on the margins of the stream which runs through our park is a recent venture. It is far too soon to decide that it is a success because this is their first season so all we can say is so far, so good. If we still have some and they are gently increasing in five years time, we will hail it as a success.

Of all the plant families in the world, orchids are by far the most complex. The sub group of disas alone has about 170 separate species and that does not take into account multitudinous hybrids. Mark is not trying to get to grips with the detail. He just accepts gratefully what local orchid expert and friend, George Fuller, gives him to try out. As far as we know, it was the dainty little Disa tripetaloides which gave us white flowers earlier in the season and these larger red ones in flower now are from the more common D. uniflora. It is the natural habitat of the disa orchids which caught our attention. They occur in damp conditions on the margins of streams and waterfalls, predominantly in South Africa. That is why we hoped they could be naturalised on the margins of the stream where they are a great deal more exotic than the thuggish yellow Primula helodoxa. You need a situation where you can control floodwaters however, as we do with a weir and a flood channel, or our frequent torrential downpours will scour out marginal plantings.

If Wikipedia is correct, the tuberous root of the disa orchid is used to manufacture maltodextrins, used in artificial sweeteners. How curious is that? Mark is a bit concerned at the absence of the Mountain Pride Butterfly here, that being the natural pollinator for D. uniflora in South Africa. We are not at all sure that our monarch butterflies, which we have in abundance, are up to taking on additional duties in this respect.

In the Garden this week: January 28, 2011

• A point of clarification from last week: if you want to try water retention crystals (Saturaid, Crystal Rain or similar) on a dry lawn, you must rake them in, not just leave them scattered on top. Otherwise you will just hoover them all up with the lawnmower.

• If you read the article on the food pages of our local paper last Tuesday about pine nuts, you may be interested to know that they are easy enough to grow here. Pinus pinea, the Italian stone pine, is the most common variety though there are other species suitable for seed (pine nut) production. However, and it is a big however, as soon as it comes to harvesting the seeds and peeling off the outer coating of each seed, you will realise why they are relatively expensive in the supermarket. You are more likely to decide that they are actually extremely cheap to buy instead.

• If you needed an extra reason to get motivated to plant a winter vegetable garden, the Australian floods may be it. Vegetables are tipped for hefty price rises this year – it is all a matter of supply and demand. So start digging. If you are working on grassed areas skim off the top layer of turf and stack it to one side to rot down. Or, if you are not determined to be organic, spray with glyphosate (formerly known as Round Up) which will also kill off most of the perennial weeds (but not clover). Current evidence is that glyphosate is safe to use when applied according to directions. It has been around for many years now so there has been time to discover lingering ill effects or contraindications.

Last weekend's rain means it is safe to return to planting out herbaceous material

Last weekend's rain means it is safe to return to planting out herbaceous material

• With the heavy rain last weekend and more forecast, we have resumed planting but only of herbaceous material, not woody trees and shrubs which will get stressed when we next dry out again. Herbaceous material is quicker to establish itself and to get its roots out and it responds much faster to watering if necessary. I have been digging, dividing and replanting an enormous clump of Ligularia reniformis (the tractor seat one) – but cautiously. It is within reach of a hose just in case.

• If your potatoes are showing signs of blight (dark brown wet patches on the leaves), you have to be in really early with a fungicide spray to stop it. If the foliage is already collapsing, it is too late. Dig the potatoes immediately and you may save some of the crop. Delay and the blight will also infect the potato tubers. You have to remove all the diseased foliage and tubers to try and stop the fungus from remaining. Either burn the affected plants, put them out in the rubbish or hot compost them. Don’t just throw them in a heap or cold compost them. It is this blight (Phytophthora infestans) that caused the Irish potato famines.

• On the grounds that a few phone calls asking the same question may indicate a landslide of curiosity out amongst the readership, I found the rolling compost maker shown in Outdoor Classroom last week at Mitre 10 Mega in New Plymouth. This is not to say that other outlets do not also have it in stock – I did not look further.

Make your own compost hot mix, step-by-step (part two of three)


Compost part one, saw us looking at low tech, low input ways of dealing with green waste. Here we look at how to make hot compost which sterilises the mix.

1) Compost needs five ingredients:
a) nitrogen
b) carbon
c) oxygen
d) water
e) microbes.
You need to actively manage the process with a hot compost mix. The common failing of the black plastic drum as a compost bin is the lack of carbon and the lack of oxygen which means you get a soggy, sludgy mess. Carbon comes from dry, woody material – twigs (cut up small), newspaper (needs to be shredded or scrunched up), wood chips, sawdust (not tanalised), wood ash, dried leaves. As we make a lot of compost, we get much of our carbon content from the mulcher or wood chipper. Carbon content should comprise close to half the total volume of your compost and, as it is often bulkier, it creates air spaces in the mix.

2) The other half, or a little more than half, of your compost ingredients comes from the green waste (which is the nitrogen component). This includes all green leafy waste, animal manure, food scraps and lawn clippings. Compost microbes will come in with the grass clippings, or you can add some of your old compost mix (the old twiggy bits can go through again).

3) We simply pile it all in a heap until we get enough to work with. Wooden compost bins are a tidy option for the small garden. You need three – the first to accumulate the waste, the second to make it in and the third for compost which is ready to use. Make sure that you can remove all the boards from at least one side to make it easy to move the compost through the bin cycle. Each bin needs to be around a cubic metre at the least. A ring of chicken netting is the low tech method of keeping your growing compost pile contained and is probably easier to work with though less tidy.

4) When you have sufficient volume to work with, adding nitrogen in the form of fresh grass clippings, fresh animal manure, urea or blood and bone will give your compost a kick start to generate heat. Mix it all up. When done by hand, the garden fork is the usual tool to mix. We do the mixing with a baby tractor which is admittedly easier but a little excessive for small town gardens. Cover the heap from here on.

5) The heat should reach between 55 and 75 degrees Celsius within a few days. Turn the heap again – sides to middle – to get the whole lot working. You can see the clouds of steam pouring out of our heap which indicates heat. There will be no worms or insect life in hot compost mix. The heat should also kill off weed seeds and undesirable pathogens. Ideally, turn a third time a few weeks later.

6) Cover and leave the compost to cure for a couple of months or longer. The compost will now cool down and it should be light, friable (almost fluffy), clean and have no offensive odour. In our high rainfall climate, we recommend covering with something reasonably waterproof to prevent the goodness from being leached out. We use old weed mat weighted down at the base. You can also use heavy duty black polythene. Boards or corrugated iron are common on a tidy compost bin structure.

Part three – making cold compost mix.