10 March 2013
Budding the Honey Locust
As part of our winter tree planting last season, we planted hundreds of Honey Locust (Gleditsia Triacanthos) in various locations along the flats. One of the main reasons they were chosen was the glowing endorsement by John Weatherstone who has now enjoyed the benefits they provide to his pasture and livestock for around 20 years.
As John points out, in short they can:
- serve as a fire retardant
- produce nutritious pods for stock fodder (up to 100 kg per mature tree per season. These pods have a nutritive value equal to oats grain or quality pasture and are produced with no extra costs once the trees are established.)
- produce foliage which is also palatable to stock
- reduce the amount of water reaching the water table (thereby helps fight dryland salinity)
- provide good shade which allows the pasture to stay greener for longer and reduce stock stress during hot periods, whilst late spring leaf-out and early autumn leaf drop minimize shading in the cooler months
- grass grows right up to the base of the tree
- recycle nutrients (which had leached below the root zone of pasture plants, these are recycled back onto the soil surface through the foliage and pods)
- produce timber (a dense hardwood with a number of uses)
- produce excellent honey
- enhance our view (it’s an attractive tree that is green in summer, turning gold in autumn).
One of the downsides is that seedling trees often produce nasty thorns; big enough and sharp enough to puncture tractor tyres (even if selected from a thornless tree) which ain’t what we want. So we’ve gone about grafting onto our rootstock to ensure we get the trees we want, which is heavy pod-yielding, thornless trees.
Of course, for propagation material I went no further than John’s place and he took me to a couple of his favourite trees from which a number of years ago he weighed 100kg of pods in an average season. (Even at the conservative density we have planted, a yield of half that quantity will result in 5 tonne/ha whilst maintaining excellent pasture quality beneath)
Honey Locust are widely sold as ornamental trees in the nursery industry, and I have followed their standard practice of budding during summer. Here’s a quick rundown of how to go about it.
Select healthy and vigorous new season growth.
Cut off the petioles (base of the leaves emerging from the stem) about 5mm from the stem and place material in the fridge for 24 hrs to harden up.
For ‘budding’ you are basically cutting off a bud (vegetative growing point emerging from the stem, situated just above the leaf axil) from a tree with the characteristics you’re after and placing it onto your root stock. I have used a piece of red peach stem here for good contrast.
To go about it: First, make a cut at about 30 degrees, 50-10mm below the bud, 1/4 of the way through the stem. Second, cut from 10mm above the bud and slice through at the same depth as your intial cut until the piece comes away. Third, immediately cut a similar sized piece of material from the rootstock and place the desired bud in its place. The most important part of the exercise is to get a good match of the cambium layers. The cambium is the thin green line at the inner edge of the bark, just outside the wood. It is the only part of the tree trunk that actually creates new growth, therefore the only part that will graft.
Here’s Rohan taping up his graft. The bud will be checked and the tape removed in 4-6 weeks when it has taken. The secatuers in the picture are for cutting the top 1/3 of the rootstock growth off to encourage the plant to put energy into the new material. Once the new growth has progressed, the remainder of the rootstock can be chopped off.
A warning. We have a fairly harsh climate where we are, with very heavy frosts and hot dry summers. If you are in a more favourable clime, think carefully before planting these trees as they can become a weed, and are declared noxious in Queensland.
*(John Weatherstone is an inspirational Australian farmer who, having seen his property turn to a dust bowl in the 1982 drought , changed his farming approach. John has planted tens of thousands of trees all off his own bat, creating a diverse agroforestry system whilst maintaining a productive farm and nursery business. You can read about his story in this pdf.)