Paul Cereghino wrote:Roots and shoots are connected. The roots provide water and nutrients to the shoots, the shoots provide sugar/sun energy to the roots. The energy of the plant (in terms of nutrient/sugar) shifts over the course of a year. In spring stored energy flows from the roots into the new growth and flowers, and seed, and is complemented by new energy captured by the leaves. After floweing, energy begins to flow back into the roots (as well as the seeds which become a mobile energy reserve for the plant). The strength of these flows depends on the species and the environment, and this is a simplification, because energy and materials are flowing all over all the time, but the pattern is true.
That is why cover crops are tilled under at flowering when top growth has peaked. It is also why cutting at flowering but before seed is viable is the most effective time for controlling unwanted plants. Some plants are always ready for disturbance, by retaining a large energy/nutrient reserve in the roots. Once ALL shoots are gone, a plant is operating on reserves (like a biochemical battery). If it is cold or dry, a plant can sleep (go dormant) and live off of reserves for a very long time. If it is warm and moist, plants will try to grow shoots. Some plants (like our Himalayan blackberry, Rubus procerus), you need to remove all shoots for 2 growing seasons to kill it, and this has been done with black landscape fabric.
I wonder about pigs? I have a vague memory that lupine makes poor browse, but a don't know about the roots.
The other way would be to not worry about the ground layer, and just use the lupine as a mulch crop as you move over time into a tree and large shrub system... edible forest or woodland vegetation. It would be interesting to observe at what level of canopy closure that the lupine becomes less dominant. It also appears the the lupine dominance is seasonal. Lupine are strong in spring, but allow other species to compete, as energy flows back to roots and seeds. The soil is likely loaded with lupine seeds, which I suspect are very durable (given that some species come back after forest fire!). So if you kill the existing plants, you will still have new recruits every time there is a disturbance.
Also, if this species is connected underground (not common among Lupines, but I don't know your species), you have a different problem, as there is no 'individual' but rather a energy trading network that is more difficult to disrupt.
Henrik Hellman wrote:Thanks all for your input!
Seems like there are very different varieties with different hardiness etc. I think we have the wild invasive kind here too.
You can really see it spreading.
Paulo: Great info! You suggest digging up their roots by hand. This seems like soo much work You dont think covering with something would work at all?
I dont really know how perennials work with their root system... Do they "live" underground even if the plant is not being able to develop over ground or do the roots
break down eventually?
I have begun removing the seeds, so I will have LOTS of them. I will look into the possibility of mailing some abroad if there is interest.
Kevin Franck wrote:
Oh, i live in Göteborg. I'm an American transplant. I'm not real sure what or how much you want to do. Just remove what you want starting out small than then go from there. I'd wait and start in late April. You know how long it takes for spring to actually get here. This summer BTW was the lousiest growing season with cool temps and almost constant on and off rain.
Henrik Hellman wrote:
Small world, I'm not far from Göteborg, 10 miles south east! I can imagine growing season wasnt so good this summer. Greenhouses do make a lot of sense here
You have ablog you said, you have a link maybe?
Anyways... The plan is to turn this lupin-invaded area to a place for growing lots of veggies, fruit trees berries etc.
I'm still very confused on how to get rid of all these lupins. I'm very curious about sheet mulching, maybe I'll try that on a smaller area and see if it keeps them down. I can also dig up the roots on another area and see how it works out...