In the Garden January 29, 2010

The buds and flowers are edible and it may be pretty but the Cape Pond Weed is dangerously invasive in our waterways and should be shunned at all times

The buds and flowers are edible and it may be pretty but the Cape Pond Weed is dangerously invasive in our waterways and should be shunned at all times

  • If you have hydrangeas full of fresh foliage but precious few or no flowers, the likely problem lies in your winter pruning. Most hydrangeas set flower buds on last season’s growth so if you cut them off at ground level or too low down the stems, you have cut off all the next season’s flower buds. You can not make them flower this season but get some advice before you prune again this coming winter or be less brutal.
  • The end of January usually heralds the time when garden centres start to take delivery of spring bulbs which are sold dry because they are dormant at this time. If you are after anything beyond the usual mass runs, you will need to start haunting your garden centre because anything rare and choice is likely to be available in small numbers only and to sell out quickly.
  • Summer is a good time to give some attention to water gardens and ponds. You are less likely to suffer from hypothermia and the water can start to get pretty green and algae ridden as temperatures rise. If you don’t have fish, you are highly likely to have a breeding ground for mosquitoes unless your water is flowing. We saw a solar powered mini fountain in a friend’s garden in London which was to counter mosquito breeding but don’t know how widely available they are here. The alternative is a plug-in water feature to keep the water moving. A squirt of CRC across the surface of the water will kill the larvae. You may need to seek advice from your garden centre on algae treatments. The simplest water feature of all is a smaller growing water lily plant in a large bowl and a single water lily flower can be a vision of simple perfection. Never but never unleash oxygen weed into flowing streams and shun the African Cape Pond Weed (water hawthorn or Aponogeton distachyum). We know how invasive both are and Mark battles infestations annually in our stream and ponds.
  • If you have an onion crop, the indication that they are ready for harvest is when the stems turn brown and bend over. Once you have dug the onions, they need to dry out for a few days before storing them. Plaiting them or using mesh onion bags is to allow continued air movement so they don’t rot. Don’t store them in plastic and hanging them is better than boxes on the ground. The same storage rules apply to garlic.
  • It is the last call for sowing sweet corn. Given a reasonable summer and autumn it will mature just in time and then as temperatures drop, it will hold in the garden (it stops growing) part way into winter which greatly extends the fresh corn season. You may never buy frozen corn again.
  • With the many fruit trees sold in recent years, some readers will be picking their plums if they can beat the birds. The best time to prune and shape your plum tree is straight after harvest. You reduce the chance of silver blight entering the tree if you summer prune. The same applies to cherries, both ornamental and fruiting, almonds and indeed all stone and pip fruit and their ornamental relatives.

Flowering this week: anigozanthos, probably a flavidus hybrid.

The Australian anigozanthus requires perfect drainage in our conditions

I have never been up close and personal with Kanga and certainly not so near that I can examine her feet, so the reason why the anigozanthos family are widely referred to as kanagaroo paws eludes me. While the flowers are slightly furry, that doesn’t seem sufficient reason to liken the two. But these interesting clumping, evergreen perennials from South Western Australia are worthwhile additions to the sunny garden, if for no other reason than that they flower most of the year.

The critical issue with anigozanthos is perfect drainage. Apparently flavidus is more tolerant of damper conditions than the other species (which may be why this yellow one thrives where we have lost others over time) but we are only talking tolerance of Australian damp which is not at all the same thing as Taranaki damp. Perfect drainage, a raised bed and very open conditions are still recommended.

Modern breeding has led to the commercial release of a range of jewel-like colour combinations going well beyond the common red and yellow toughies, more into the rosella parrot colourings. We have tried a number of these over the years and gradually lost the lot – you should have more success if you garden in sandy, coastal conditions. But the reliable yellows and reds give consistent and curious flowers in our rockery and are also good as a cut flower. This yellow plant puts up flower spikes to around 150cm and, bless, they hold themselves up without staking. Many others are a great deal more compact and with flower spikes closer to 20 or 30cm

Anigozanthos are frequently available in garden centres.

In the garden this week January 22, 2010

  • Only mad dogs, Englishmen and dead keen gardeners are doing much in the ornamental garden at the moment. But do stop weeds from going to seed if you want to save yourself a great deal of work later. If you catch them before the seeds are set, you can push hoe them or just pull them out and leave them to frazzle in the sun. But if you can see seed heads formed already, you will have to gather them up and either put them out in the rubbish or hot compost them. Weed seeds will survive baking in the sun and indeed survive most people’s compost heaps which don’t get hot enough to sterilise. If you have rubbish collection, the wheelie bin is the safest option for seeds.
  • While you can’t be doing much planting in the ornamental garden, you can at least summer prune, limb up, tidy up and deadhead. We tend to be spring garden specialists in this country and can look rather dull, green and tired in full summer. A grooming round can freshen it all up considerably.
  • We summer prune the roses constantly, trimming back to leaf buds where possible, deadheading and generally tidying up the bushes. If you don’t spray your roses, this is an important process to look them looking half way decent. The books all recommend watering and feeding too, but we don’t tend to get around to this.
  • Most clematis which have finished the first flush of flowering and which may now be sporting an unfashionable powdered white look (powdery mildew) can be cut back to a few centimetres of growth. Feed them, give them a good drink and they will spring back into fresh growth and even flower for you in about six weeks. You can not do this to all clematis, but most of the hybrids that you buy will respond to this treatment.
  • In the vegetable garden, harvest continually to encourage the likes of beans, cherry tomatoes, cucumbers and courgettes to continue producing fresh crops.
  • Even though we have had little real summer yet, the end of January signals the time to get late sowings of corn in to carry you through to early winter. Planted after that, they are unlikely to mature in time.
  • Basil is best pinched out to encourage bushy plants.
  • Most garlic will be ready to be harvested and alas after a bumper crop last year, we are going to be lucky here to have sufficient to keep the vampires at bay. Store in cool, dark conditions with good air movement – in other words plait them in traditional style or recycle mesh onion bags.
  • If you enamoured of the Brussels sprout, you need to be getting in plants right now if you want to be confident of a harvest later. Keep up with sowing fresh salad greens – a little often is the key.
  • The new gardening programme on Prime (Sunday at 7.00pm) is all about learning to veg garden but unless you fit the demographic (urban dwelling female, under 40, upwardly socially mobile and probably drinking skinny milk decaf latte and driving a people mover), it may not inspire you.

Gathering seed: a step-by-step guide with Abbie and Mark Jury

A Major Mission in the Rockery

The refurbished rockery looks a little barren in places but below the mulch are many bulbs waiting to spring into fresh growth

The refurbished rockery looks a little barren in places but below the mulch are many bulbs waiting to spring into fresh growth

My current activity started in a very minor way. I must thin out the Cyclamen hederafolium and nerines in the rockery, I thought yet again but this time I had my timing more or less right. The nerines look fantastic in flower in autumn but the clumps had become so large that they had forced themselves up out of the soil and the foliage hangs on right into late spring, swamping treasures around them.

What I did not realise when I started was that the task was going to be so major that I would spend eight hours a day for several weeks, taking apart the contents of the rockery pocket by pocket. It has become a Major Mission.

Cyclamen hederafolium is the autumn flowering species, formerly known as neapolitana. It is a gem which flowers over a period of months in white and, more commonly, cyclamen pink. After many years, decades even, they sure were overdue for thinning out. They grow from flattish, round corms and a large one is about 10cm across. Some of ours were closer to 25cm across and as I gently excavated, I found them up to three deep. In fact, my thinning exercise yielded up around 60 litres of surplus corms with which Mark plans to carpet woodland margins and add to his naturalised bulb hillside in the park. That is six 10 litre pots, in case you are wondering how I arrived at the 60 litre figure.

Having started, I found that the English snowdrops and black mondo grass which share some of the same rockery pockets were also in desperate need of thinning. And while I was about it, I figured the heavily compacted soil could do with aeration and a light dressing of compost. Then the rocks needed some of the lichen and moss scraped off them and some of the pockets had soil levels which overflowed. In fact a complete spruce-up seemed in order. And of course the areas which I did looked so fresh and clean that I felt I had to continue. I am still not finished but I am a driven woman and will not desist until I have done the lot. I have uncovered rocks and divisions in the pocket beds that we did not even know existed.

Rockeries are not in fashion these days, not at all. Ours is a 1950s style rockery using raised beds in island formation. There are a lot of rocks, brick and concrete in it and it must have been a major exercise to build. I had not noticed before that the largest rocks are in the beds closest to the drive. The further you go from the vehicle access, the smaller the rocks get and the more freeform concrete construction there is. I can understand why. Some of the largest rocks must have been very difficult to move.

The basic rockery concept is to emulate the conditions of an alpine meadow. We can’t do alpine, though we have tried. We lack the winter chill and are a great deal too humid with rainfall evenly spread all year. Alpine meadows are cold deserts kept dry in winter by a coat of snow and ice. So our rockery plants are by no means traditional. No gentians or edelweiss here. But what it gives us is a section of garden which is highly detailed, where the pictures are small and individual and baby gems can be admired in close up view. It is entirely different to the big picture style of garden where form, colour and flow are what dominate. Bulbs rule in our rockery, especially those of a miniature or dwarf persuasion. We use cycads, venerable dwarf conifers and some smaller growing perennials so the area is not totally bereft of woody and herbaceous plantings but they are merely the backdrop.

Best guess is that there are well over 500 individual pockets in our rockery. And the skill that has my gardening ability stretched to its absolute limit is the creation of differing combinations in at least some of those pockets. So one may contain nerines for autumn colour, moreas (peacock iris) for early spring and a small perennial such as a prostrate campanula for summer interest. I can not claim that I get triple layering in them all. I wish. Alas some will be bare during parts of the year because they are too small or I Iack the material or skills to plant in layers. But the structure provides the year round interest and does not demand to be filled to capacity twelve months of the year. Some bulbs will only flower for one or two weeks but in that time, they are the daintiest and most ephemeral of delights which would be lost entirely in larger garden beds.

Mark’s parents both loved the rockery. Stepping out from the house, there is always something different to view. Day to day maintenance is relatively easy. We have always worked to keep it weed free, to restrict the occasional invasive bulb (it is why one has separate pockets to keep those with wandering ways in a confined area) and beyond the occasional light mulch and ongoing tidying, it is not generally labour intensive. With most of it being raised, it is not back breaking either. Many bulbs are happy to continue in an environment which is relatively poor. But there comes a time when the soil is so impoverished and compacted that treasures start to go back and thugs multiply so much that the competition is to survive, not necessarily to flower well.

Bulbs are not gross feeders so we like to spread a thin layer of compost on top to mulch and give a light feed only. Not every plant is precious and that realisation has been wonderfully liberating. Some plants are past their use-by date. Some are just in the wrong place. Some have multiplied too well so there are too many of them. Going though centimetre by centimetre has been like a voyage of discovery. I have worked out that I can average about four square metres a day if I stick at it. With about 100 square metres of rockery, it is a mere 25 days work.

Some people like to garden in containers to keep little treasures apart and to be able to give different conditions. Despite my current intensive effort, I think the rockery concept takes less work overall for more aesthetically pleasing results. Maybe the rockery will stage a fashion comeback. If the thought of assembling, placing and securing all those rocks defeats you, there is an alternative in what we call the carpet garden, but for more thoughts on that garden genre you will have to wait.