It was bound to happen sooner or later. The big headline last week concerned the Tom-tato. Let me start at the beginning of this tale. You know and I know that the tomato and potato belong to the same family – Solanaceae.
They both come from the same continent – South America.
One has been developed in Western society for its edible fruits – the Tomato – while the other has edible tubers – the potato.
It is not surprising that when the potato plant flowers, it then produces fruits that look, when small and green, remarkably like small green tomatoes. Still with me?
The difference being that the fruits of the Potato are deadly poisonous. Conversely, I have never heard of a tomato plant with edible tubers.
Switching tack now, we have a propagation technique in horticulture called grafting where two different species of the same genus can be joined together physically to make a new plant. For example, take a crab apple seedling, grow it on for a couple of years, chop the top off it and join onto the cut surface of the rooted end, a cut twig from a Cox’s Orange Pippin, bandage it up until the wound heals and hey presto the shoot will grow into a tree with cop fruits on it, supported by the roots from a different apple family. The nearest we have to that in human terms is the organ transplant.
Stage three, this grafting process has been developed, in some circumstances, to influence the vigour of the above ground part of the new plant and sometimes to combat soil borne diseases. In the latter case, for many years now gardeners have grafted tomato varieties on to seedling tomato rootstocks that are resistant to certain soil-borne pests and diseases. You can now buy these grafted plants from most well-known seed suppliers. I tried a couple this year and I have been well pleased with the results.
To that headline now – why not graft a tomato plant on to a potato rootstock? Harvest fruits and tubers. No problems with compatibility and over the years, gardeners have tried this successfully as a challenge and for a bit of fun but now it will be commercialised. What do you think? I think it is a step too far, an abomination.
Staking trees
In our weekly Beechgrove list of viewers’ questions, I noticed one asking for help with how to stake trees growing in half barrels. When you think about it, that seems a daft idea – picture the scene 10 years down the line, a tree 3m tall with a crown width of 3m, rooted in a half barrel. One puff of wind and over it will go. I exaggerate of course and linking to my previous topic, the trees could be grafted on to dwarfing rootstocks especially for pot culture. That does work, we do it all the time, especially with fruit trees.
That said, they will need to be staked to ensure that the root system remains stable until it has spread throughout the soil mass in the barrel. How is it done then?
You revert to using a modification of the ‘invisible’ staking method employed by landscape contractors who are planting large heavy duty standard trees often on new industrial sites where upright posts would be inappropriate and oblique posts and guy ropes would get in the way of grass mowing operations.
It is no secret that my DIY skills are pretty pathetic and I am now about to reveal an example – it is not neat but it is working so far. The picture tells the story.
Take one section of a concrete drain pipe and stand it on end and ‘voila’ a planter. Fill with drainage and soil, plant one pot grown tree, with conventional stake and then, cut two pieces of timber to fit the diameter of the planter but have to be hammered in to position, one either side of the tree trunk, down on to the top of the root ball and it is securely trapped. Cover with mulch and you can’t see that the pieces of wood don’t match. What the eye doesn’t see …
Flaw? Yes, you will also note that the edges of the horizontal timbers are quite close to the base of the tree stem, which in time will increase in girth. Then I’ll have to take out a notch on each side, won’t I?
I should stress that this technique only works when there is a significant ball of soil surrounding the roots or when they are container grown. It would not be an option if the tree were bare-rooted when being planted.