Digging out a Strelitzia
Where to begin
After a few queries about how to move or remove a Strelitzia, I decided that it was high time to remove a small specimen so I could study the root structure. A S. nicolai plant had seeded itself a few years ago next to an unsightly telephone pole on my lawn. Initially I welcomed it as I imagined it would at least soften the view, but as it began to encircle the pole I began to have doubts as to whether this was altogether wise.
We had removed a medium sized clump of S. reginea previously so we used the same method here.
Having had some good rain during the previous week, the soil was reasonably soft. A trench was dug all around the plant. This needs to be wide enough to stand in so as to have space in which to maneuver as one digs deeper. Our gardener, Vincent, is particularly adept at this kind of digging, having removed innumerable tree stumps on previous occasions.
The digging process
There were a few woody, dried out roots quite close to the surface of the ground but the thick, living roots started about 25cm below the soil. Vincent kept digging vertically until he had passed the depth of the main mass of the root ball - about half a meter. Here he changed to a pick and began to dig under the plant. As we were not going to re-plant, we were not too worried about slicing through the roots. Once Vincent had removed some of the soil all round from under the solid base, it took a quick pull to tumble the whole thing out of the soil. The whole process took him an hour and a half.
This of course was only a small, relatively young plant but I would use the same system for mature specimens as well. It may prove impossible to remove the whole plant in one piece as we did here. In this case it would be necessary to hack chunks off around the plant so as to get to the middle. I also suspect that the base will become deeper as you move towards the older growth. It is also a good idea to cut off a substantial amount of the foliage and stems. The stems and trunks are fibrous and a good swipe with a machete will usually be all that is needed - but beware! If you have no experience with this vicious tool, rather use a saw.
The structure of the base
Bear in mind that Strelitzias are members of the banana family and grow in much the same way. I had a good look at the structure of the root system. There are only a few roots that travel horizontally, with most of them going straight down into the soil. These roots are very fragile, being juicy and brittle but with a strong and tough root running down the center. The entire base of the plant itself is made up of separate individual plants, each with its own set of roots. The plant itself consists of numerous layers of brittle, juicy plant matter - something like an onion.
Pitfalls to avoid
I recently had an experience where a few S. nicolai plants were removed from a garden which I subsequently took over. The plants removed were in both a rockery area as well as in deep, soft coastal sand. They were removed in some haste I believe, and some plant matter remained underground. The plants in the rockery sent up replacement shoots within 6 months. This is understandable as the entire rockery area would have to have been disassembled to reach the roots. The plants that were in the sand have also begun sending up shoots - 18 months after the initial removal! From this I have learnt that it is imperative to remove as much material as possible. I doubt that the re-growth is from pieces of root as I have dug up root sections and found them to be rotting. But take a look the the pictures below. While removing our plant we found a number of these little nodules which broke off very easily and were soon lost in the soil. These are the buds of new plants which, if left beneath the surface, will start to grow, even when very deeply buried. Another possible reason for re-growth is that, due to careless use of the pick or inattentive clearing up, sections of the base of individual plants are severed and left behind in the soil.
This point may seem obvious to most, but I only really got the knack a few of years ago: When digging the trench, make sure that the loose soil is piled well away from the edge or it will keep cascading back into the hole.
Digging up a Strelitzia for the purpose of re-planting or sub-dividing
Use the same method but take more care. Before you begin digging it might be a good idea to tie a rope around the leaves so that they are out of the way. It is annoying to dig or swing a pick when you have leaves getting in the way. Dig the trench about 25 cm away from the base all round to preserve root matter, and make it about 75 cm wide, as you will need more space to move around. As you will want to preserve as much root matter as possible, dig well below the base of the plant (about 75 - 100 cm from ground level) before you begin to chip in underneath. Once you have loosened the plant from the ground, it needs to be lifted out of the hole. Don't try to move it on your own. We used a large piece of shade netting which we placed into the trench on one side of the plant and then eased the incredibly heavy plant onto it. The plant was then lifted out and carried to its new position - another crater that had been prepared in readiness.
If you want to subdivide the clump, use a knife to cut the shoots away from each other. Always try to ensure that a piece of root is attached. If splitting a plant means that one piece will have no root, rather leave the two intact. When I didn't know any better I tried planting sections that had no root at all - the plants have survived for 7 years but they still only have two or three leaves and are going nowhere. With care and plenty of water and food, rooted plants should flower within two years after transplanting, but I have known some plants to sulk for up to four years.
The picture below shows a rooted plant, but leave the leaves intact.