Flowering this week: Eupatorium sordidum

Like a giant fluffy blue ageratum on steroids

Like a giant fluffy blue ageratum on steroids

It is a member of the wider daisy family but it looks like the annual fluffy blue ageratum on a massive overdose of steroids. In fact it is a perennial woody shrub from Mexico which reaches about 3 metres high and nearly as wide with big leaves (slightly felted) and big fluffy, fragrant flowers in lilac blue. Normally it is in full flower for our spring garden festival but it is a little late this year. It is not very hardy and presumably it didn’t like the cold winter.

We grow it outdoors here but we saw it in the covered house at Kew Gardens in London under a different name and then we saw it in a garden in Italy under yet another variation but it appears that all are more or less correct: Eupatorium sordidum, Eupatorium megalophyllum, Bartlettina sordida or Bartlettina megalophylla. It does not appear to have a common name so it is referred to here upon occasion as that giant overgrown blue ageratum-like plant. You are not likely to find it for sale but it does grow easily from cuttings if you find somebody with a plant.

November 13, 2009 In the Garden

  • We are starting to dry out already. Keep a close eye on container plants. If they are showing signs of stress, it is likely they are either badly root bound (should have been potted on when we told you in winter), hungry or dried out. To get water back into dehydrated plants, a squirt of dishwashing detergent or surfactant will help absorption. However, ignore any advice given elsewhere to add water holding crystals (also called Crystal Rain) to potting mix for anything other than annuals. In our climate with high rainfall, woody plants and perennials will rot out in winter if you add these crystals, however tempting it may be in summer to use them. Partially burying pots and containers into the garden (called plunging) can reduce excessive drying out. It also stops pots with taller plants from blowing over in the wind.
  • It is late in the season for planting out woody trees and shrubs, especially if they are large or root bound. Our advice is to heel them into the vegetable garden until autumn. If you are determined to plant into other garden positions, make sure that the root ball is soaked right through. A watering can just will not do. It can take hours (or leave overnight) to get the water into the middle if it is very dry. Once planted, mulch to conserve moisture and keep an eye on the plant until Christmas at least to ensure that it has not dried out again.
  • If you spray for thrips on rhododendrons (the leaf sucking critters which cause silver leaves), get the first application on when you see the insects on the under side of the new growth. We are not keen on this practice and will only spray one or two special plants ourselves. We would be much happier to hear of gardeners opening up around the plant to encourage air movement, feeding and mulching to encourage more health and vigour and taking out plants which are particularly susceptible to replace with healthier selections. We have drawn a line under many of the cold loving German and American hybrids here and said that we just can not grow them well in our mild, coastal conditions.
  • It is the optimum time for planting kumara runners. This is one plant which really loves warm, light soils.
  • As soon as we get more rain, fungi are likely to attack potatoes and tomatoes. A copper spray applied as soon as the foliage has dried out after rain is usually necessary if you wish to guarantee a harvest later.
  • Brassicas will be under siege shortly, if not already, from much of the insect population and in particular the dreaded cabbage white. This is the single biggest reason for not growing brassicas for summer harvest in our climate. If you don’t wish to spray with an insecticide, you have to start getting creative with old net curtains and the likes. However, this only stops the cabbage white laying more eggs and does nothing to deal to existing caterpillars in residence. We will be eating our remaining brassicas soon and not replanting until autumn, with the exception of brussel sprouts which are best sown in the summer for harvest next winter.
  • Leeks can be sown now.

Flowering this week – Olin and Caroline (rhododendrons of course)

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Olin O. Dobbs - a vision in blackberry and Caroline Allbrook - enchanting in lilac

It is only appropriate to keep with rhododendrons as our Rhododendron Festival steams on so it is two half-siblings this week. Olin O. Dobbs is the mysterious and unusual one (they share Purple Splendour as a father) – spectacular conical trusses in the deepest blackberry colour, rivalling Blackberry Nip rose but Olin does not fade out. Unfortunately, despite being much sought after when in flower because of the striking hue, Olin is difficult to propagate (basically needs to be grafted) so is virtually unavailable on the market these days. He also prefers a colder climate and gets infested by thrips here so does not look crash hot as a plant for the other 50 weeks when not in flower. We don’t mind because we will trade all that for two or three weeks of blackberry splendour.

The half sister, Caroline Allbrook, is a pretty, pale lavender which is a reliable performer every year here. Caro also distinguishes herself by holding well when picked which is by no means true of all rhododendrons. Great flower truss, easy to grow and should be reasonably readily available in the marketplace. She does look rather fine planted beside Olin in our carpark area but if you could use the burgundy foliage of loropetalum to contrast, in the absence of Olin.

For devotees, the seed parent of Olin is Mars and for Caro it is the species yakushimanum.

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We were very taken by the juxtaposition with the purple car parked alongside by a garden visitor

In the Garden 6 November 2009

  • There is precisely no gardening going on here this week as we meet and greet visitors – just the daily garden equivalent of housekeeping with the mower, the blower vac, hose, leaf rake and push hoe. It is a good exercise in keeping a garden looking sharp by maintaining freshly mown lawns and defined edges.
  • Start deadheading rhododendrons as they finish flowering. Oiling your fingers (olive oil is fine), means you don’t get the sticky residue hanging on. If you only have a few plants, deadheading all of them certainly tidies them up but if you have many, then take the time to work our which ones set seed and give these priority. Try and avoid breaking off the new shoots which are coming through just underneath the spent flower.
  • Be vigilant now on weeds. Early season control saves a great deal of work later on. It is warm enough now to push hoe and on a fine day, the sun will dry them to a frazzle. You can only do this if you catch them before they reach seeding stage. If you let them get too large, you really need to cut off and remove the seed heads or you are just spreading the next generation.
  • Do not delay on laying garden mulch before summer. It needs to be down before the ground dries out. Laying mulch suppresses many germinating weeds, conserves moisture, improves the look of a garden and if you are using a nutritious mulch (compost) it adds nutrition and structure to the soil. It is a myth that laying pea straw adds nitrogen to the soil because the peas store all the nitrogen in their roots not their tops. If you are worried about your carbon footprint look for local alternatives – we don’t grow peas commercially in Taranaki and your cheap garden mulch is shipped from points quite some distance away.
  • Top priority in the vegetable garden is getting the crops in which have the longest growing season – melons, aubergines, tomatoes, cucumbers, gherkins, kumara, Florence fennel and corn. You can continue sowing peas but it might be a little late for getting the Christmas Day harvest through in time unless they are already growing. Keep sowing the salad veg for continued harvest (lettuce, mesclun, radishes, micro greens). You can get sowings of basil and coriander in now from seed. Making pesto at home is so easy that that you will wonder why ever bought it.
  • Plant main crop potatoes if you have not yet done so.
  • Last year’s notes tell me that we had a triumph eating our first bowl of home grown strawberries at this time. We certainly won’t be achieving that milestone this year. I don’t think there is even a hint of red visible yet. This can be attributed to the use of a cloche last year.

Growing vireya rhododendrons from cuttings: step-by-step with Abbie and Mark Jury

A step by step guide by Abbie and Mark Jury first published in the Taranaki Daily News and reproduced here with permission as a PDF.

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