May 1, 2009 In the Garden

* It is great to see the NPDC hort staff offering practical workshops on technical gardening skills. First up tomorrow (Saturday) and again on Monday is a free demonstration on pruning stone fruit trees. For absolute novices, they are the fruit which have large seeds called stones (rather than small pips) – in other words plums, peaches and apricots. Whoever is taking it will know what they are doing and if you are have fruit trees at home, here is an ideal opportunity to learn more. Just turn up tomorrow or Monday at 11am at the orchard in Brois St.

* It is autumn clean-up time with a vengeance in the ornamental garden. Try not to keep putting it off because when winter really bites and the ground gets cold, it can be much harder to motivate yourself. Cut back leggy perennials, rake up (or rake out and disperse) large patches of fallen leaves which can get blown into one area, cut back plants which flop onto the lawn or path at this time of the year and generally get right through the garden, even if you do much of it with the ever useful leaf rake.

* Look out for spring bulbs, many of which are just pushing through the surface. Stomping on them does not do them any good and can break off the one flowering shoot on some varieties.

* Mark disappearing plants which you want to lift and divide. Some plants are what are known as deciduous perennials – in other words they go underground entirely in winter. It can be very difficult to remember their exact location later.

* Don’t delay any longer on sowing lawns and if you are in a cold spot you may already have missed the boat. You want enough warmth to germinate the seeds and get the growth started before the cold of winter.

* If you followed our advice a couple of weeks ago about making the first cuts to wrench a larger plant that you wish to move, you can follow up now with the second cuts to the other two sides of the roots.

* Veg gardeners have pretty well harvested everything harvestable, bar late potatoes and have long ago sown and planted their winter veg. It is now planning time for spring. While some advocate fertilising and mulching the bare ground now as part of preparation, we don’t see any logic to doing this until there are plants in the ground to benefit. We subscribe to the sow it down in a green crop brigade. You can however be preparing the garlic patch which will be planted soon. Sow broad beans and in mild areas you can get a crop of carrots in for the spring. Rocket and micro greens can be sown in favoured spots, under a cloche, in a glasshouse and in seed trays for a quick out of season green harvest.

* The quote this week comes from British story teller and author Sam Llewelyn: In gardens, beauty is a by-product. The main business is sex and death.

Avocados and figs in Taranaki

As I prepared guacamole this week, I realised I have never written about growing avocado trees in Taranaki, despite this fruit being one of our own mainstays. With a lull in the vegetable garden, we are relying on avocado and parsley to give the daily green intake. So herewith the short introduction to growing your own avocados.

1) Avos are frost tender and don’t like the cold so you need to live in a warmer, coastal area to grow them successfully in Taranaki (apologies to all those of you who live inland).

2) Buy a grafted, named variety. While it is easy to grow the seed, it is unlikely that a seedling will fruit satisfactorily, if at all. We have by far the most success with Hass.

3) Avocados are trees. Small trees up to five or six metres but definitely not shrubs or bushes. Give them space to grow and full sun.

4) Drainage is critical. Avocados are very sensitive in the roots and particularly vulnerable to phytopthera. Plant them in a position with brilliant drainage.

5) Be prepared for the fact that some years you will get a very poor harvest, or even no crop at all. The fruit takes around eighteen months to mature to picking stage but is most vulnerable at the time of fruit set when an untimely frost or spell of really bad weather can mean that no fruit is set.

There are brilliant years in between which make up for it when you have avocados for breakfast (a slice of Vogel’s toast spread with a thin layer of marmite and topped with avo), for lunch (sliced over leftovers or served with anything and everything) and for dinner (guacamole or in salads). The tree will pay for itself in one good season. Any surplus fruit, we notice, is gladly received by those around us, especially at this time of the year as the price is rising in the shops and the quality of the fruit is getting better. The oil content of the fruit rises over time and the current fruit was actually set in spring 2007. Be wary of fruit that is picked when immature. We harvest from our two Hass trees from Christmas to August or September. If it were not for the battle with the rats and the waxeyes, we could harvest for even longer.

So the bottom line on avocadoes is that it is well worth growing your own if you have the right position and conditions. Naturally that is predicated on the assumption that you enjoy eating them or giving them away.

There is still an open verdict on figs here. I adore fresh figs and I have never understood why you can buy them on every fruit stall in London but never see them for sale here. It wasn’t until I found some at the roadside stall where I buy my free range eggs that I had even thought of picking them green and letting them ripen off the bush. But of course you must be able to. All those figs I have bought in London can not have been tree ripened. They are not exactly a local crop there and as they become soft and squidgy when ripe, they must be shipped over from warmer climes in a firmer, green state.

I am looking at our Brown Turkey Fig with new eyes. It sets an early crop which reaches full size but the birds always beat me to the harvest. They are quite happy to eat the green fruit. And the second crop fails to mature. Now I am thinking that we need to manage the bush better and it should be manageable.

Most fruiting figs are large deciduous shrubs which clump and sucker. The leaves can be reasonable decorative, especially when they turn golden in autumn but overall they are not aesthetically pleasing plants. If you think about where they grow in the Med and North Africa, you will realize they want maximum warmth and sharp drainage but they don’t need high fertility soils and mollycoddling.

It being a shrub, rather than a tree, I think we should be able to net the fig next year to keep the birds at bay. And it seems to me that we need to actively thin out some of the foliage and the crop of fruit to encourage better ripening and more size to the figs. Added to that, I shall maybe sacrifice my belief in tree ripened fruit and experiment with picking earlier and ripening in the sunroom. Our fig is planted in full sun, up against a dark coloured water tank but you are likely to achieve more success if you have a warm concrete wall close to the sea.

Unlike avocados, you can grow figs easily from cuttings or suckers so you may not have to buy one. Over time, no doubt we will see more selection taking place in this country to choose cultivars better suited to our conditions but let’s face it: mild, humid, wet and fertile Taranaki is never going to emulate Mediterranean conditions so maybe we had better be grateful for any fresh figgy crops. Apparently fresh figs are absolutely divine served with Parma ham and blue cheese (I learned this from National Radio and the morning recipes) but I have not yet had sufficient to warrant laying in the Parma ham. I live in hope.

April 24, 2009 In the Garden

• The autumn rains made a brief appearance and then disappeared again so we are indeed dry here. But this is Taranaki, not Australia, so you can be positive that the rains will return with a vengeance and sooner rather than later. Saturday is the likely date at time of writing.
• There is considerably less evaporation at this time of the year with cooler temperatures so you should not be worrying too much about the dry spell. Container plants will need watering every few days but you should not be needing to water the garden or lawn. But if you are planting any trees and shrubs, you need to ensure that the roots are completely saturated before planting. Hosing down after planting will not do the trick.
• If you have bought dry spring bulbs from the garden centre, get them planted as soon as you can. If they are looking very dehydrated, you can soak the bulbs overnight in water. You have missed the boat on lifting and dividing bulbs already in the ground. They will be on the move.
• Pruning and shaping should be in full swing in the ornamental garden although if you are working on winter or spring flowering shrubs, you do not want to be cutting all the flower buds off. Think in terms of thinning and shaping rather than hacking back and trimming all over. Do not leave clipping hedges any longer past this weekend.
• Rhubarb can be lifted, divided and replanted. Think of it as a very hungry perennial (commonly referred to as a gross feeder). Rhubarb responds well to rich soils, well dug over and fed with humus. It also wants plenty of moisture and full sun. The rule of thumb is that a third of the rhubarb patch should be renovated each year.
• Strawberries need replanting on a two year cycle. If you have some growing, it is likely that they will have put out runners. These are what you lift and cut off, replanting into fresh ground with well cultivated soils.
• From the irrepressible Pollyanna School of Positive Thought comes the unattributed quote: “Don’t grumble that roses have thorns, be thankful that thorns have roses.”

April 17, 2009 In the Garden

* If you are intending to move any large plants this winter, start the wrenching process without delay. This initially involves making cuts to the roots on two sides of the plant. Calculate how large a rootball you can reasonably move (the larger the better) and cut from there. In a couple of weeks, follow up on the other two sides, and underneath if you can and then carry out the removal operation two weeks later. All this is to reduce stress on the plant and to encourage it to start the process of forming new roots where you have cut. You don’t need to bother with small plants.

* As you do the autumn clean-up round in the ornamental garden, get a layer of mulch onto all the garden beds possible. Any mulch suppresses weeds as long as it is thick enough (3cm or so). Our standard mulch here is home made compost which also provides nourishment and texture to the soil. Mulches of bark chip, gravel, stones and the like (fortunately the dreaded scoria seems to have disappeared) do not do anything for the soil. Pea straw is very fashionable and very expensive (so we do not use it) but is ideal as a mulch, if rather intrusive visually. Last year’s calf shed wood shavings are excellent but don’t put it on too thickly. Sawdust can be used if not tanalised but needs considerable caution. Don’t dig it in. Only people of no aesthetic sensibility use weed mat as a mulch and we hope in this day and age that nobody who reads this column would even contemplate using black plastic.

* If you covet a politically incorrect green velvet sward, you can fertilise your lawn at this time of the year. Use a cheap NPK fertiliser or Bioboost.

* Anything planted in the vegetable garden from here on is more likely to be ready for harvest in early spring, rather than the depths of winter. All the usual candidates – brassicas, winter greens, spring onions, carrots, broad beans, beetroot and even leeks (from plants not seed) – can be put in now.

* If you have a favoured warm, frost free position, you can put in an early crop of potatoes. Pick a quick maturing variety such as Swift or Rocket. For some unfathomable reason, being able to dig a very early crop of potatoes earns maximum brownie points amongst serious gardeners. Make sure the potatoes are well sprouted before planting and do not waste your effort unless you can be sure of protecting them from winter frosts.

* Although the potato hails from South America, apparently 90% of the world’s potato production occurs in Europe. In the somewhat harsh climate of much of Britain, it was the prime source of Vitamin C in the two world wars, thereby holding scurvy largely at bay. The modern diet of the very thin potato crisp may not be sufficient to achieve the same outcome.

Death to the Orangeberry Plant

My rubus pentalobus is under a death sentence. What, you may wonder, is rubus pentalobus. It has taken me some time to get a grip on its proper name and I may soon forget it again but most of us know it as the orangeberry plant. It is a ground cover plant, marketed widely in recent years with a key selling point of producing edible fruit.

I am guessing that in its native Taiwan it may produce more fruit but it has the reputation of being very reluctant in this country. I was optimistic with the second season and a solid mat of it in a hot, sunny position. It put up a good number of small white flowers in spring but these translated into precious few orange berries in summer. And berries might be slightly overstating the case. Certainly they were orange but at little larger than a glass pin head and held singly, berries seemed an unjustifiably generous descriptor. Indeed, Mark just looked incredulous when we spotted the first fruit. It is difficult to describe the taste. I think the entire crop was two each so the best I can say is fruity, in moderation.

But it is not the ever so slightly disappointing harvest that had me donning the black hat to pronounce the death sentence. No. What the rubus lacks in fruiting capacity, it more than makes up in vigour. Knowing that it could be a little rampant, I used it in a defined border where I wanted the unity of a single ground cover to set off a little collection of topiaried camellias. It was confined by concrete edging on three sides and a box hedge on the fourth. Not that the rubus was going to let that stop its inexorable advance. The moment I turned my back, it would leap the concrete edging and get its roots into both the lawn and the gravel paths. I could cope with that, but its inclination to weasel its way through the buxus and even climb started to ring alarm bells. Ground covers that can moonlight as climbers are a worry. Added to that, after only two years, the ground is such a mat of congested roots that it is near impenetrable and the rubus is even threatening to overpower my valued camellia specimens. Spending several hours every couple of months trying to thin and contain the plant does not seem worth the effort to me.

I will not be digging the rubus to pot up and sell. That seems altogether irresponsible. Though if anyone has a large clay cliff they wish to retain, a precipice perhaps, a landslip or maybe a large stretch of coastal erosion which they were thinking of retaining with concrete slabs, this plant may be just the ticket. I would guess that it has the potential to turn up on Regional Council’s banned list sooner rather than later. We will be resorting to gyphosate to carry out the death sentence. The tangled mass of rampant root makes digging it out difficult. You have been warned. Keep this plant controlled and under close supervision.

A bonsai camellia under threat from the thuggish rubus pentalobus.

A bonsai camellia under threat from the thuggish rubus pentalobus.

Like his father before him, Mark has a deep distrust of plants with weed potential. Maintaining a large garden is a delicate balancing act at the best of times without allowing rampant colonisers to escape. There are no annual forget-me-nots here. Charming they may be, but they did not earn their common name lightly. Let them into your garden and it takes years to stop them seeding everywhere. Rampant seeders, subversive clumpers, overpowering thugs – no matter how pretty, such plants are not welcome. We have tended to add violets into the category of invaders with their inclination to spread and their resilience. Indeed, despite my best efforts in several places in the garden, clumps of violets keep staging a come back. And down in the paddock is a clump which Mark refers to as Grandma’s violets. In fact I think they are a relic of his great grandmother’s garden from the late 1800s. Now we think the violets will make a more acceptable ground cover than the rubus. Their invasive tendencies are not too serious. In 120 years, the rubus would have colonised the better part of Tikorangi whereas Grandma’s violets have just gently survived all competition and kept going. Their flowers are prettier than the rubus, too. I think they have earned a recall.