Have you planted a green manure crop this year?

A few weeks ago we recommended planting a green manure crop as one of the fastest and easiest ways to improve your soil before you plant fruit trees. This week we’re showing you what the crop should be looking like by by now, and what to look for.

A green manure is a fast-growing crop of (usually) annual plants, and it’s one of the quickest ways to improve soil fertility and add organic matter to your soil.

The last couple of times we’ve planted new orchards, we’ve first put in a green manure crop before we’ve planted the fruit trees because we’re always aiming to increase the biodiversity under our fruit trees—it’s one of the best ways we can provide the right habitat for useful insects that help us keep the pests under control.

Sas planting a green manure crop in the nursery
Sas planting a green manure crop in the nursery

This year we planted a green manure in the block where we’ll be planting the new nursery in winter. The seed mix included grasses, legumes (nitrogen fixers) and herbs – grasses to add bulk organic matter to the soil, the legumes to add nitrogen, and the herbs to add a diverse mix of nutrients. If you’re not sure what seed to choose, you can check out our recommended plant lists (and even some suppliers of organic seed, if you’re in Australia) in this short course.

We’re always aiming to increase the biodiversity in our soil – it’s one of the best ways we can provide healthy soil to grow trees, as well as habitat for useful insects that help us keep the pests under control.

The more diversity you can get into your garden, the healthier your fruit trees (and all your other plants) will be. And if you’re growing your own food, you definitely want that food to be as healthy and nutrient rich as possible.

Clover starting to grow
Clover starting to grow

It’s always a good sign to see lots of clover seedlings coming up. We particularly like having clover because it’s a nitrogen fixer (taking nitrogen from the air and putting it in the soil where the trees can use it).

Clover is quite spreading and so out-competes less useful weeds, and it self-seeds so it will persist in the orchard for years.

Experience has shown us that even though we plough green manure crops back into the soil before we plant the trees, plenty of clover seedlings will still come up, and over time it will gradually spread throughout the orchard floor.

A bean plant in the green manure crop starting to grow
A bean plant in the green manure crop starting to grow

Before we plant the new nursery in July, we’ll be turning the crop in. We use a rotary hoe, or the disc behind the tractor, but in a home garden you can either turn it in with a shovel, or just mow it and leave it on the soil – it’s not quite as good, but the worms will eventually take that lovely organic matter underground for you.

Getting ready to plant a new tree
Getting ready to plant a new tree

One of the unfortunate consequences of using large macinery like a disc is that disturbing the soil so comprehensively provides the perfect environment for opportunistic weeds such as capeweed (below).

Beautiful but unpopular capeweed
Beautiful but unpopular capeweed

We appreciate all our weeds, and even the much-despised capeweed has many fine qualities, but it’s not the plant we prefer to see in the orchard, as it tends to out-compete more useful plants, without conferring the benefits of a nitrogen-fixer.

Just one word of warning – if you are going to turn in your green manure crop, try to leave at least a couple of weeks between doing so and planting your trees, because the rotting green material can become quite hot as it breaks down, and you don’t want to burn the roots of your baby trees!

So in a classic case of “do what we say, not what we do”, here’s our top 4 tips for looking after your soil when you plant your fruit trees:

  1. Plant a green manure crop
  2. Turn it into the soil at the site where you are going to plant a tree, preferably a few weeks before you plant
  3. Disturb the soil as little as possible when planting the tree
  4. Re-seed the area with preferred understorey plants.

What do you think of pears?

Do you have a pear tree in your garden? Are you interested in growing them?

A beautiful Winter Cole pear
A beautiful Winter Cole pear

We’re on a bit of a mission here at the farm to bring pears back into fashion, because when you get them right, they’re really delicious.

They also really lend themselves to preserving, they’re relatively bomb proof in the garden (as long as you keep the birds off), and they improve your food security by extending the fresh fruit season.

However they tend to be one of the more ignored fruits, and there’s a couple of reasons why.

One is because it’s very hard to pick them at the right time so they will ripen properly, though this is easier with some varieties (including the various types of nashis) than others.

Ripe nashi pears
Ripe nashi pears

Many types of pears go floury if you let them ripen on the tree, so they have to be picked when they are mature (but not ripe) and then stored in a coolroom or fridge for a few weeks before allowing them to ripen at room temperature. That means there’s a few variables you need to get right.

First, knowing when they are mature can be tricky; it’s about making sure that the seeds have gone completely dark brown and plump, and that the fruit has enough starch in it.

Secondly, you need to be patient and let the fruit stay in cold storage for long enough before you try to ripen them, or they just won’t ripen. This is something we’ve got wrong many times ourselves in the past – in our eagerness to get them to market, we’ve often either picked too early or not left them in the coolroom long enough.

Pear blister mite
Pear blister mite

Pears are relatively easy to grow. They can get a few problems, like Pear blister mite (above), Black spot (a common fungal disease) and of course the very common Pear and cherry slug, but none of those problems are too destructive or hard to control.

They’re usually very reliable trees, they thrive in conditions that other trees don’t like (e.g., soggy, or frosty areas) and it’s pretty easy to get them to crop well. 

Gorgeous white pear flowers
Gorgeous white pear flowers

Plus, they’re beautiful trees to have in the garden, with large glossy green leaves, beautiful white blossom, and a stunning autumn display. 

Clearly we’re big fans of pears, which is why we’ve been steadily expanding the number of varieties we grow on the farm. It also means we’re able to offer some unusual heritage varieties at Carr’s Organic Fruit Tree Nursery (like St Michael Archangel, Glou Morceau, and Beurre Clairgeau, as well as the much sought after but hard to find Lemon Bergamot.)

If you’re tempted to plant a pear tree but don’t feel confident in how to grow them, take our short course Plump pears and quirky quinces for information about pests and diseases that affect these fruits, how to prune them, and a bonus bundle of 5 tried-and-true pear and quince recipes.

Pears featured at the National Gallery of Australia
Pears featured at the National Gallery in Canberra


Will a multigraft fruit tree suit you?

Multigraft fruit trees are kind of awesome.

A multigraft apricot tree with two varieties
A multigraft apricot tree with two varieties

This is a great example — an apricot tree with both Katy and Trevatt apricot branches. Katy is an early apricot that is a bright orange colour, firm texture, slightly oblong shape and terrific flavour that combines sweetness and tartness. It’s also a reliable cropper.

Trevatt is a more common apricot that you may have heard of — it’s a heritage variety (dating from the 1900s, developed in Mildura), and is completely different to Katy. It ripens about a month later, it has pale lemony-orange skin, and is a super-sweet apricot with very little tartness. It also has a much different texture, ripens from the inside, and is much softer — it can even go a little mushy if allowed to get overripe.

So, will a multigraft suit you? They’re much less well-known, and many gardeners are a little hesitant to try them out.

It’s almost a no-brainer that a multigraft is a better use of the space in your garden, unless you have space for a LOT of fruit trees and would prefer to have whole trees of each variety. Considering that a mature tree can easily yield up to 40 or 50 kg of fruit (or more) in a good season, it usually makes sense to spread the harvest over a longer period, rather than have a massive glut to deal with all at once.

There’s a couple of other great reasons that multi-grafts can work well:

  • pollination: in this example both varieties are self-fertile, but even self-fertile trees can benefit from having pollen from another variety close by, and this can help to increase yields;
  • spreads the risk: apart from the issue of gluts already discussed, some seasons just don’t favour some varieties. For example, if you happen to get a frost just at the time when the Katy are at full bloom, the Trevatt may be later coming into bloom and might therefore have less frost damage. Another scenario we’ve seen many times is rain affecting one variety that is almost ripe, causing it to split, while another variety that is still a month away from picking can escape relatively unscathed — so the more varieties you have, the better your chance of at least getting some fruit every year!
  • disease resistance: different varieties may be more vulnerable to particular diseases, like blossom blight or brown rot, either because of the difference in their ripening times, or just the natural resistance of that variety.
A fruit salad tree with a plum and two apricots
A fruit salad tree with a plum and two apricots

A fruit salad tree is like a multi-graft on steroids!

This extends the concept to include different types of fruit on the same tree, rather than just different varieties of the same type of fruit. In the example we’ve included here, you get both!

This tree has three varieties:

  1. Katy apricot (described above) – ripens late Nov
  2. Trevatt apricot (described above) – ripens late Dec
  3. Angelina plum – an early season European plum, very sweet, with beautiful dark purple skin with the traditional dusty-looking ‘bloom’ on the skin. These plums are incredibly delicious and versatile – you can eat them fresh, dry them, bottle them, jam them or make them into wine, just to name a few. They’re also a favourite for the classic European plum dumplings, or plum cake. They’re a really good plum to include in the garden.
Beautiful Angelina plums
Beautiful Angelina plums

Angelinas ripen in January – so with just one tree you’ve already extended your harvest over three months, as well as given yourself a pretty good variety of fruit to enjoy and preserve.

We love creating multi-grafts in our on-farm nursery (called Carr’s Organic Fruit Tree Nursery), and have quite a lot of different combos on sale this year — you can see our selection of multi-grafts here.

At the moment we’ve limited it to apricots and plums (though we have plans to extend it to apples, pears and peaches), but there’s heaps more you can do in your own garden, by learning how to graft new varieties onto existing trees.

It’s such a brilliant and easy way to extend your fruit season and increase the variety of fruit in your diet that Grow Your Own Fruit Trees for Free
is one of our favourite short courses, and probably the best one to start with if you’re new to grafting. We also have specialist courses on individual grafting techniques when you’re ready for them.

There can be a couple of drawbacks with multi-grafts though.

One of them is that the trees can come out of the nursery a slightly unusual shape (as you can see from the photo above), and so require a bit of careful management to establish as a useful ‘vase’ shaped tree.

The other main issue is that one variety may dominate the tree, and again, may need some attention when pruning to help keep the tree balanced. A handy tip is to plant the tree with the weakest branch pointing north, where it will be favoured by more sunlight.

But really, the management issues are usually handled easily during the regular “getting to know you” phase of your relationship with the tree, and once established, they usually settle down and crop beautifully.