Mares Tail Summit
In July Peter Wright of Lady Road Allotments visited and gave a fascinating talk on the plant. His notes follow to help anyone rid themselves of this very invasive weed.
To get rid of horsetail is a war, one battle is not enough. The war will go on for several years, you will win most battles if you are as stubborn as the horse tail, but on the way you will lose some.
I have been fighting my war for 16 years, it is not over yet, last year I had one fir tree on the battleground, but this year I am being invaded by foreign troops across paths.
Know your enemy.
The plant has been in existence for at least 400 million years, it is a survivor, it has no natural predators in the UK, except humans. It is not a series of individual plants but an integrated root system, sending up green shoots to absorb sunlight and thus give energy to the massive root system below ground. Just digging and turning the soil over will eradicate it, as happens with annual weeds. Small, broken sections of root, less than 5cm long can survive and start growing. A mature plant is dormant in the cold Scottish winter, in spring it sends brown cone like fruiting spores which are wind dispersed, the spores can set new plants but the main invasive method is from the rhizome like roots. Following the fruiting spores the plant sends up green Christmas tree like shoots, these provide chlorophyll for the rooting system and food, essential. The outer layer of the green shoots is hard and water repellent.
Root system. Below the shoot the root system is horizontal at about 300mm below soil level searching for your precious nutrients and invading new areas, I call this the “food and pioneer corp root”, below this horizontal level vertical roots plunge down searching for water, this I call the “water corp, below this another horizontal root can form at1 / 2 metres deep this I call the “mother lode”. Deeper water roots can again go vertically down.
The food and pioneer roots are slightly hairy, they have modules every 3 to 4 cm, the modules are food stores and from them spring the Christmas trees. The tip is strong and can grow over 1 metre in a year, it will find its way round obstacles. It can punch through paper.
The water roots are smoother, and seem to have adapted to penetrate harder soil conditions, they do not gather food, they can punch through softtish sandstone.
The plant invades by sending out the “food and pioneer” root horizontal underground, as it progresses it sends up the Christmas tree for chlorophyll and water roots down. The water roots are less frequent than the “Christmas trees”. After about 3 years the initial invasion will start sending up fruiting spores.
What are its strengths.
Rapid growth underground, ability to regenerate from the smallest bit of root, whether “pioneer”, water root, or mother lode. Can shake off weed killers, no known predators, will invade through poor, good or any soil. Root system can store food in times of lean years, root system is integrated and therefore very difficult to kill off completely, used by the Victorians to stabilise railway embankments.
What are its weaknesses.
Needs chlorophyll, without the green it cannot produce food for the root system, the root system then draws on its stored reserves. Does not like cultivation, two edged sword, digging out can also spread bits of root, hoeing removes the green but not the root. The outer layer can be bruised to allow systemic weed killers in. If the food stores are not replenished the root system starts to weaken.
Techniques mass extermination
Digging, in spring before the green bits have reached the sun, only use a fork as a spade will cut through the root, tease the root out and try to get as much as you can, dig down and follow the root. Double digging, using a fork sometimes gets you to the mother lode. You must be very diligent. Dry the roots on an open grid, once dry they burn well, do not compost, do not put in trade waste, burn.
Spraying Glysophate works, and is the recommended weed-killer, but it will take several applications to clear an area. Walk over green “firs” to bruise the outer layer, then spray, repeat at fortnightly intervals, as the root system is so extensive as the plant absorbs the glysophate, its effect lessens the further the weed killer has to penetrate. This first season forget about trying to grow crops if you have an intensive infestation. I am told that a dilute vinegar works, but I have not tried this technique and I do not know what vinegar does to the soil. Glysophate on contact with the soil is alledgedly neutralised, and does not affect the good microorganisms in the soil, there is debate about these industry claims.
Individual shoots Very difficult as they come up in the middle of your crop, if you can dig out following the root, if the shoot is too close to crops the plastic greenhouse technique can be used. Wear plastic gloves, dip your fingers into glysophate gel and rub the shoot carefully not to break it, but enough to bruise. Take a plastic bottle cut the base off and place it over the shoot, the greenhouse keeps the rain off and encourages growth/absorbtion of the glysophate. Once a week with glysophate in a spray remove the plastic bottle top and spray into the plant.
Joint action You must get the plotholders around you into the battle, if not you will always have pioneer roots waiting to get to your good soil. One method which has worked for me is dig a trench on the troublesome border, it was a path and place thick double layered compost bags against the path, keep the path well mown to reduce the green shoots. These top green shoots will compost if they have no brown roots attached, but better be wise and burn the lot!!
Finally It is not easy, and there is no magic wand or silver bullet, hard work over many years will eventually solve the problem.
PJW July 2019
To get rid of horsetail is a war, one battle is not enough. The war will go on for several years, you will win most battles if you are as stubborn as the horse tail, but on the way you will lose some.
I have been fighting my war for 16 years, it is not over yet, last year I had one fir tree on the battleground, but this year I am being invaded by foreign troops across paths.
Know your enemy.
The plant has been in existence for at least 400 million years, it is a survivor, it has no natural predators in the UK, except humans. It is not a series of individual plants but an integrated root system, sending up green shoots to absorb sunlight and thus give energy to the massive root system below ground. Just digging and turning the soil over will eradicate it, as happens with annual weeds. Small, broken sections of root, less than 5cm long can survive and start growing. A mature plant is dormant in the cold Scottish winter, in spring it sends brown cone like fruiting spores which are wind dispersed, the spores can set new plants but the main invasive method is from the rhizome like roots. Following the fruiting spores the plant sends up green Christmas tree like shoots, these provide chlorophyll for the rooting system and food, essential. The outer layer of the green shoots is hard and water repellent.
Root system. Below the shoot the root system is horizontal at about 300mm below soil level searching for your precious nutrients and invading new areas, I call this the “food and pioneer corp root”, below this horizontal level vertical roots plunge down searching for water, this I call the “water corp, below this another horizontal root can form at1 / 2 metres deep this I call the “mother lode”. Deeper water roots can again go vertically down.
The food and pioneer roots are slightly hairy, they have modules every 3 to 4 cm, the modules are food stores and from them spring the Christmas trees. The tip is strong and can grow over 1 metre in a year, it will find its way round obstacles. It can punch through paper.
The water roots are smoother, and seem to have adapted to penetrate harder soil conditions, they do not gather food, they can punch through softtish sandstone.
The plant invades by sending out the “food and pioneer” root horizontal underground, as it progresses it sends up the Christmas tree for chlorophyll and water roots down. The water roots are less frequent than the “Christmas trees”. After about 3 years the initial invasion will start sending up fruiting spores.
What are its strengths.
Rapid growth underground, ability to regenerate from the smallest bit of root, whether “pioneer”, water root, or mother lode. Can shake off weed killers, no known predators, will invade through poor, good or any soil. Root system can store food in times of lean years, root system is integrated and therefore very difficult to kill off completely, used by the Victorians to stabilise railway embankments.
What are its weaknesses.
Needs chlorophyll, without the green it cannot produce food for the root system, the root system then draws on its stored reserves. Does not like cultivation, two edged sword, digging out can also spread bits of root, hoeing removes the green but not the root. The outer layer can be bruised to allow systemic weed killers in. If the food stores are not replenished the root system starts to weaken.
Techniques mass extermination
Digging, in spring before the green bits have reached the sun, only use a fork as a spade will cut through the root, tease the root out and try to get as much as you can, dig down and follow the root. Double digging, using a fork sometimes gets you to the mother lode. You must be very diligent. Dry the roots on an open grid, once dry they burn well, do not compost, do not put in trade waste, burn.
Spraying Glysophate works, and is the recommended weed-killer, but it will take several applications to clear an area. Walk over green “firs” to bruise the outer layer, then spray, repeat at fortnightly intervals, as the root system is so extensive as the plant absorbs the glysophate, its effect lessens the further the weed killer has to penetrate. This first season forget about trying to grow crops if you have an intensive infestation. I am told that a dilute vinegar works, but I have not tried this technique and I do not know what vinegar does to the soil. Glysophate on contact with the soil is alledgedly neutralised, and does not affect the good microorganisms in the soil, there is debate about these industry claims.
Individual shoots Very difficult as they come up in the middle of your crop, if you can dig out following the root, if the shoot is too close to crops the plastic greenhouse technique can be used. Wear plastic gloves, dip your fingers into glysophate gel and rub the shoot carefully not to break it, but enough to bruise. Take a plastic bottle cut the base off and place it over the shoot, the greenhouse keeps the rain off and encourages growth/absorbtion of the glysophate. Once a week with glysophate in a spray remove the plastic bottle top and spray into the plant.
Joint action You must get the plotholders around you into the battle, if not you will always have pioneer roots waiting to get to your good soil. One method which has worked for me is dig a trench on the troublesome border, it was a path and place thick double layered compost bags against the path, keep the path well mown to reduce the green shoots. These top green shoots will compost if they have no brown roots attached, but better be wise and burn the lot!!
Finally It is not easy, and there is no magic wand or silver bullet, hard work over many years will eventually solve the problem.
PJW July 2019