Monday, December 10, 2012

Pumkins and lemon trees...

I've written this post for Margaret of Stone's Throw Cottage, who is making a fantastic effort removing environmental weeds and enhancing her already wonderful garden by planting some delicious edibles! :)

Margaret has the perfect location for a forest garden.  She has many established trees in an upper canopy, several fruit trees in the middle layer, different levels, a slope, sunny areas, cool areas and lots of native vegetation.

She has decided to clear away a big area of environmental weeds (Wandering Trad and English Ivy) and replace this with indigenous plants for attracting wildlife, providing habitat for local species and also increasing the biodiversity in her garden.

Yesterday, I saw her and her partner (well, mostly her partner!) struggling to rid an old veggie bed of a bad infestation of Wandering Trad, both being desperate to plant out some pumpkins.  When I suggested that they relax, take their time, and plant the pumpkins under the nearby lemon tree instead they thought I'd gone a bit bonkers.

They wouldn't be the first! :)

So Margaret, get yourself a cuppa and let me explain...

The lemon is shallow rooted.  It is not great at getting nutrients out of the soil and also tends to dry out because the roots are closer to the surface.  Lemons often suffer from nutrient and moisture deficiencies as a consequence.  Add to this it being on a slope, with the soil there being a silt loam, and your lemon can really be doing with a bit of extra help.

First prune your lemon a bit:  remove diseased and broken branches.  Then remove any that rub together.  Finally, check that the centre is open enough to allow light in and air to circulate.  This will get you more, better quality fruit and reduce the chance of any fungal diseases.  It will also let the light through to below.

Now place some stepping stones in like the spokes of a wheel to give you access for fruit picking.

Next, you can plant some perennial bubs in a ring around the tree.  I would suggest you do this just outside the dripline, which means where the trees outer most leaves are.  The tree still has a bit of growing to do, so we want these bulbs to be where the dripline is likely to be once the tree is bigger.  Try 30-40cm outside the current dripline.

You can also add a second ring directly around the trunk of the lemon if you wish.

Choose bulbs that are spring flowering and dormant in the hot parts of summer, to reduce any competition for water.

Daffodils are a great bulb to use as most of the plant is toxic and it puts pests off, hopefully keeping them away from your tree.  Also consider alliums such as chives, garlic and garlic chives, which of course you can eat - do not get them mixed up with the daffodils!

Alliums are very attractive to beneficial insects who like to eat nectar.  They also tend to attract aphids, which will go to the alliums rather than your tree.  Insects with predatory larvae, such as hoverflies, ladybirds and lacewings, will be attracted to the chives in particular, lay eggs there and their larvae will consume vast numbers of the pest species.

This way, you protect your tree and create a breeding ground for beneficial insects who will do a fantastic job throughout your garden.

These bulbs also suppress grass and will therefore reduce your urge to whipper-snipper.  You wouldn't believe the number of lemons that die because of over zealous whipper-snipping :)

The third thing to do is consider how else you can create an insect habitat to further benefit your tree.  There are many plants that can be used to create an insectory and these can be planted inside your circle of bulbs, so will be under the branches of the tree.

Try edible herbs such as dill, fennel, coriander, which will attract more beneficial insects, including species of tiny parasitic wasps who will sort out any pests that the hoverflies, ladybirds and lacewings haven't taken care of.

You can also plant some lovely flowering natives nearby, not under the tree, that will attract birds who will enjoy poking around the lemon and eating any insects or grubs that they find.  Correas are great for birds and will go well on your slope.  You can also get some low growing bottle-brushes and banksia species that will attract birds, create ground cover and give other wildlife such as lizards and frogs (they'll eat your snails and slugs!) somewhere out of the sun to shelter.  Couple these with some rocks and you'll be creating a wonderful habitat for them.

Now you have your insect attractants in place, you now need to make sure that you're giving your lemon, and all your other plants, a good boost of nutrients.  But stop - don't chuck on that citrus fertiliser!

What I mean is, you need to get in some plants which will accumulate nutrients or draw these up from deep in the soil.  These can go under your tree.

Perennials such as white clover, which will provide bee forage, stay green throughout the year and are low growing will fix nitrogen from the air, making it available to the plants around it.  You can use more interesting plants such as lupins, or edibles such as pea and beans.  The peas and beans can be sown in early spring and late summer, giving you harvests at different times of the year.  There is also the possibility of using a low growing native ground cover such as Acacia cognata 'Limelight'.  This does better with a some protection from the sun and will fix nitrogen as well as providing a living mulch cover.

For deep rooted plants, Comfrey is the classic choice.  Chicory and yarrow are also used, but you will already have some of the best nutrient accumulators to hand: dandelion and plantain :)

They all have deep tap roots that will bring nutrients to the surface for the lemon and shallow rooted plants to use.  The nutrients become concentrated in these plants and they will eventually die down once nutrients are being naturally cycled.  In the meantime, they can all be pulled up every so often and just laid on the soil to rot down and release their nutrients again.  Comfrey is a great addition to compost heaps and can be used to make comfrey tea for spraying on your garden.  It can generally be slashed down several times over summer and left to compost in place too.

The dandelion of course is edible: the leaves make a great salad addition, the roots can be used to make soft-drinks, tea and alcohol.  These you can test out on my in-laws next year ;)

And now, to the pumkins!!

The one thing I haven't mentioned much so far is mulch.  Your lemon really needs this to help it stay cool in summer and retain moisture in the soil around it.  Comfrey, artichokes, rhubarb and clover can all be used for this.  The artichokes and rhubarb you can eat, the clover fixes nitrogen as mentioned above, and the comfrey is a soil improver.  Nasturtiums are also commonly used under fruit trees, but one of the best things you can use is pumpkin :)

It grows to form a dense mat of spreading shoots, which will provide a fantastic living mulch around the tree and it's companion plants.  The leaves shade the pumpkins and also the ground underneath, keeping the temperature  noticeably lower than the surrounding air and preventing evaporation of water.  The tree benefits the pumpkin by keeping the leaves drier than they might otherwise be in our fairly wet climate, which will reduce fungal diseases and give you healthier pumpkins.      

If they need more sunlight, then they'll simply grow outwards more to get it :)

In autumn, once you've finished harvesting your pumpkins (and your rhubarb, artichokes and summer peas or beans!), you can simply slash everything under your tree down, or let it do this on it's own, and it will all return any unused nutrients to the soil.  In the process, it will protect the roots of the lemon from cold weather, give habitat to any small creatures that need winter shelter and provide loads of organic matter for the worms and other soil organisms to feed on.

Next year, your soil will be much improved, your lemon healthier, and your pumpkins even bigger :)

If you stick up a sign saying it's a Trial Plot and explaining what you're trying to achieve, it will explain your seeming craziness to your guests and no doubt spark some interest.  You never know, someone may have more ideas of ways you can squeeze in more of those pumpkins.

Many of the plants mentioned can be bought by seed in Belgrave.  Check out Belgrave Organics or head across the road to Sherbrooke Health Foods.  Both have a good range of organic, open-pollinated and heirloom seeds.  Get some comfrey, borage, tansy, french marigolds, yarrow, parsley, coriander, dill and some organic pumpkin seeds :)

For your veg bed with the Wandering Trad infestation:  dig carefully to break up the soil, then rake it and remove every trace of wandering trad you can find.  Then use the layering method I described the other day to prepare the bed for planting - don't do any more digging.  This just brings dormant weed seeds to the surface :)

Cover it with some manure, preferably composted, but if you can't get it composted don't worry too much.  Check down Belgrave-Hallam Road for horse manure at $2 a bag, or go to Masters and get 4 bags of composted manure for $20.

On top of the manure, layer either lots of newspaper, or some sheets of cardboard.  You can easily collect both of these in bulk from Belgrave.  This will create a perfect environment under it for worms digesting the manure and will break down very quickly to help improve your soil.

On top of this, add more composted manure, lucerne hay if you can get it, if not straw, some composted mulch, more hay, more composted mulch, and top with some organic soil-mushroom compost blend (check out Upwey Garden Centre who have some excellent quality organic soil, muchroom compost and also various mulches).  Don't worry too much about where your layers go, just keep any fresh/raw manure on the bottom.

These will all break down quickly and give you a fantastic, no dig soil :)

Plant into the lovely organic soil on top straight away, mulch around them with more straw / hay, and enjoy!

Oh, and those environmental weeds... I'll bring my gardening gloves with me next time I'm over!

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