Sunday, August 25, 2013

Give peas a chance

Although it is just the very start of spring at the moment, it is the time to start thinking about the Christmas day meal, and to start preparing the vegetable garden for the fresh vegetables that form such an essential part of our season festivities.
As much as I love Brussels Sprouts, the iconic staple of the English Christmas feast, I certainly would not want to swap a plate filled to overflowing with potatoes dug freshly from the garden once the presents have been opened, and recently harvested and podded peas.
We do not grow peas every year, as we are now constrained as to the size of our garden, and wit only two of us at home we concentrate on other vegetables, but if you have young children anywhere in the vicinity,  you probably should grow some.  They are a great vegetable for encouraging young gardeners, as they are relatively easy, normally free from diseases, and can be seen growing by impatient youngsters.  And of course, and freshly picked and podded peas taste so much better than any bought produce.
In Wairarapa, early September is a good time to get sowing, provided you have a nice well-drained site that is not too cold.  Peas generally need to be grown through the cooler months as they are very prone to mildew, and once the warmth and humidity of summer kicks in, they will just get disease and fail to thrive.  If your soil is not already supplied with plenty of organic matter, it pays to add some well rotted compost  to it,  As well as adding extra nutriment it will also improve the soil texture, making it better for the plants to grow.  As you work the compost into the soil, make sure it is cultivated to about a spade’s depth, and worked to a fine tilth.
Peas are probably best sown rather than planted out from seed trays – they are certainly a lot cheaper if you sow directly as pea seed is relatively inexpensive – but there are some pea varieties that will transplant alright, and if you just want a few plants of sugar snap peas or snow peas to grow in a container (they do very well grown that way) it might be just as easy to get the head start that nursery-grown plants offer.  The kids will love having pots of peas near the house too.
If sowing, just make shallow rows in the well prepared soil, the rows about 45 cm apart, and each seed about 5 cm away from its neighbours in the row.  If you want to give their germination a kick start you can soak the seeds in warm-ish water for an hour or two before sowing, but this is not essential.
Newly germinated seeds are like magnets for birds, and to a lesser extent, slugs, so it pays to be careful and ready for the onslaught.  I like to use a roll of chicken wire, rolled over to form a tunnel, as this can be easily removed as the plants grow up and can be used as cover for other young seedlings.  You can also just keep the chicken wire in place and use it as a base for further support by adding bamboo stakes, or even just garden twigs.  Plenty of people just start off with twigs, and that system works well too.  Make sure to put some form of slug prevention down as the plants are just popping through the soil.
It pays to make sure the peas are not too crowded in by other tall growing vegetables as that will taken some of the sun off them and will also prevent good air circulation which is the best defence against mildew.  You should have few other pests, but aphids are sometimes a small concern – just use some organic neem oil and them and that should keep them under control.  I am not sure that aphids do too much damage to the growing plants on their own but they can help spread virus diseases and you do not really want that in the garden.

Sunday, August 18, 2013

A wet spring weekend

Magnolia 'Sweetheart'
A wet weekend at this time of the year seems like a bit of a waste for the home gardener.  The imminent arrival of spring means all sorts of things are starting to move, and there are a few chores that need to be carried out.
I have been aware that the shepherds purse – Capsella bursa-pastoris to give it its Latin name – has been flowering in my iris beds, and this little member of the brassica family has many, many seeds, all of which will lie dormant in the soul to smother next early spring’s growth, so I knew I needed to get in and weed them.  They grow so quickly that leaving them for a week or two was simply not an option, so I grabbed the chance in between showers on Saturday afternoon, and got onto them. 
I was distracted in the work though, as our Magnolia ‘Sweetheart’  is just starting to flower.  It has been heavily budded for a while but the recent warm weather has made it rush out into flower and it looks outstanding on our back boundary.  I love the tree magnolias in general, and the pink shaded ones most of all. This variety has deep pink flowers, upright facing, with lusciously creamy interiors.  The flowers are medium sized (some varieties have very large flowers) and fit this tree perfectly.
I was also distracted by a planting of some new bulbs.  This year I spent my birthday goodwill on a selection of new bulbs, and they are just coming out now.  Two in particular have really impressed me, a soft pink hyacinth and a bright yellow lachenalia.
I have come to like hyacinths late in my life – I think I always regarded them a slightly fussy, overly formal plants, and associated them with the precise bedding the Dutch are so fond of, or the potted specimens you see in the supermarket.  One of my boys, after giving his mother a potted blue specimen for Mother’s Day, told her it reminded him of Dame Edna’s wig, and that image stuck with me, I suspect.
But we were given a handful of bulbs by my sister-in-law a few years ago, a mid-pink variety of great vigour that has slowly expanded and taken over a sizable container at our back door.  It looks fabulous at this time of the year with a succession of pink spires of flower giving great colour.
Over the past few years I have planted more varieties around the garden, and have a lovely yellow form (more like cream to be perfectly honest) called ‘Yellow Queen’ in the back border but this year I planted the softest pink flowered form called ‘China Pink’ and what a beauty it has been, with flowers of porcelain-like beauty of the softest cool pink, all with a lovely fragrance. 
Just across the pathway, in a bed filled with South African bulbs, is a new planting of the “Cape Hyacinth” (they are not actually that closely related), one of the new African Beauty lachenalias, ‘Romaud’.  This is a new hybrid and has flowers similar to the old fashioned ‘Pearsonii’ which has been grown for many years in New Zealand, with yellow tubular flowers, with a waxy texture, hanging from a strong stalk.  The difference is in the size – ‘Romaud’ is slightly taller but also much stockier, meaning you get a much better floral effect from the plant.

I also grew the blue form called ‘Rupert’, and I have to say that neither of these new forms are as hardy as the old types, so do not expect them to increase quickly in the garden, and give the mass effect that the old red form ‘Pendula’ gives in the garden, but they are stunning plants.

Sunday, August 11, 2013

Scentational scene

Osmanthus 'Pearly Gates'

Many trees and shrubs that flower in the late winter (or early spring) have pale flowers, often highly scented.  Flowers use scent to attract pollinators, usually bees and butterflies in the day time, so in a sense brightly coloured flowers offer no advantage.
This week I saw, or rather smelt, two new white-flowering, highly scented shrubs.  The first of these was on the ledge at the workstation of a colleague.  She had picked some flowers off her Camellia transnokoensis and brought them into work.  In the warm work environment the few sprigs of flower were enough to scent a small room, with their spicy, heady scent.  To my nose it smelt slightly reminiscent of the once common winter-flowering, shrubby honeysuckle, Lonicera fragrantissimum.
This camellia species from Mount Noko in Taiwan is sometimes given the colloquial name of ‘transnok’, and has with dainty leaves, perhaps willowy, with a graceful upright habit. The pure white flowers open from tight buds marked with deep pink. This shrub is ideal for screening or hedges, and over the past few years has become very popular.  It will grow to about three metres ultimately but is easily kept much smaller by clipping.  Like most camellias it thrives in moist, humus-rich soils with a neutral pH.
The other new plant (to me at least) was one that was recommended by an old friend (the friendship is old, not the friend!) who had seen it growing in a local garden – the slightly scarily named Osmanthus variety, ‘Pearly Gates’. 
I have grown some Osmanthus shrubs in the past – larger, autumn flowered forms mainly, with overly heady scents, but I had not seen this lovely form of the smaller growing species O. delavayii.  This is of the most fragrant of all flowering shrubs, its usually insignificant flowers having ta rich heady, fruit-filled scent. Plant hybridisers have been at work on this species and in the past few years a couple of new varieties have been released, with much larger flowers, while retaining the exuberant scent.
The better of them, ‘Pearly Gates’ has not yet become grown widespread but when gardeners learn about its good points it will soon become a firm favourite, as it has a lot of things going for it.  It is a very hardy evergreen shrub, providing good clean texture, and the white tubular flowers give a great display at the time of the year when there is not much out in the garden.  It is quite slow growing and makes a perfect hedge as it is very suitable for trimming – one Masterton gardener has planted it along a contained area between a wall and a glass swimming pool fence and it looks stunning.
This is not too fussy as to soil conditions – it will cope even with quite poor soils – and looks at its best when clumped into reasonable sized groupings.  With the addition of the scented flowers, it makes a great basal planting for near a house.  Left to its own devices it might grow to two metres, but its compact growth habit, and its ready acceptance of trimming, make it easily kept to a much smaller size.

Sunday, August 04, 2013

The camellia blight problem

At this time of the year – late winter but warming up towards spring – there is one shrub that should be coming into its own, a shrub that has been relied on to supply colour for the garden and flowers for the house for generations, that wonderful evergreen shrub, the camellia.
But over the past few years things have changed and gardeners need to be a bit more careful about how they plant and use this once ubiquitous shrub.  The arrival of the dreadful flower blight has changed everything.  This horribly disfiguring disease is caused by a very virulent fungus and effectively destroys the beauty of the blooms by browning them almost as soon as they open.  There is no sign of any effective chemical control yet, and those who passion is growing camellias must be throwing their hands up in frustration.  I know the New Zealand Camellia Society has been funding research into control of this nuisance, and overseas societies have also been throwing a lot of money at solving the problem of this scourge of camellias.
This fungous, Ciborinia camellia, lies dormant in the soil where it can live for up to five years, becoming active when a cool period is followed by warmer temperatures and moisture – does that sound like a Wairarapa spring?  It has been known in the United States for over sixty years, and has gradually spread through almost all growing areas.  It has not been in this country so long, being first reported in Wellington in 1993, but once it arrived it spread very quickly. In theory it mainly spreads incrementally, their spores moving only short distances in the wind, but I have friends who garden in very isolated places, and they all report that they have problems with this disease, so I think it is most places in New Zealand – certainly everywhere in the North Island.
There is talk about the way gardeners can be careful with hygiene among the fallen flowers, carefully picking up all infected flowers, even to the extent of taking the flowers that have fallen among the branches of a tree away, and burning them.   I am sorry, but this is wildly optimistic, and will never work in reality, as the flowers are so numerous and flower for months, and many gardeners have more than one variety.  I am no specialist in camellias, but I grow six varieties – too many to harvest the flowers.
There is also some talk of using neem oil to help control its spread, but I think even the most enthusiastic supporter of this wonderful organic spray would agree that it has not proven to be any use against this disease.
So what do we gardeners do?
There is some talk of being able to breed our way out of this conundrum, by finding resistant varieties and breeding from them.  Some recent work at Massey University suggests this might be feasible, but it looks like it will be a long way away before it is commonly available.
At the moment the only tactic to keep the pest at bay seems to be to grow varieties that flower before the disease really gets under way at this time of the year.  This will not please everyone, as some of the most delightful varieties flower in the middle of the season, or later, and the reality is that they are going to carry the horrid brown patches that typify this infection.
One obvious answer it to grow more sasanqua camellias.  These autumn flowering varieties look quite different to the more familiar C. japonica and allied species we are more familiar with.  They have a more open growth habit with narrower leaves and willowy growth in many cases.   They make wonderful wall shrubs, when allowed to splay out in one dimension, but some of the denser growing forms also make very good hedges.