How to recognise it
Newly planted plant shows poor growth in the first year when located on land that has contained plants of the same (or a closely related) species within the last 7 years.
Why it’s a problem
The root systems are weak and blackened and, as a result, the plant fails to establish properly. The impact of the problem varies by species and location.
Where you are likely to find it
It most commonly affects roses, violas, asters (Callistephus), apples, cherries and peaches. It can also be a problem for pears, plum and strawberries.
It is most commonly found when old rose beds are re-planted.
How to prevent it
There are three main options to prevent this condition occurring:
- Rest the site for 3 to 4 years (or up to 7 years to be certain) before re-planting to give any pathogens in the soil the opportunity to die away.
- Remove the soil to at least the extent of the original plant’s root spread and replace with new, sterilised soil.
- Plant the new plant within a cardboard box filled with fresh, sterilised compost or topsoil. The cardboard appears to protect the growing roots from pathogens for the first few years, the roots eventually growing through it once the plant is strong enough to deal with any pathogens in the soil.
Using mycorrhizae when planting can also assist in increasing the reach and strength of the root system more rapidly, therefore supporting the plant in its early years. A different variety of mycorrhizal fungi is available for roses.
How to get rid of it
Since it is unclear what causes re-plant sickness it is best to use the preventative measures listed above.
If you choose to plant without these preventative measures you may find that you don’t have a problem, although it is best to ensure a top class maintenance regime (including watering and feeding) for the plant to give it the best chance of thriving.
Is it good for anything?!
Other useful information
Although the cause of re-plant species is unknown, and may actually differ with differing circumstances, it may be caused by the original plant gradually building up a tolerance to pathogens within the soil (thought to be the Phythium fungus) which a replacement plant does not have any resistance to.