Hi, how should I disinfect my tomato house when we had blight and whitefly in it. Thanks.

Hi Joan, if the glasshouse or tunnel house is empty right now make sure all leaf litter and dead plant material is removed as fungal spores or insect eggs could be on the leaves. In winter open up the tunnel house and let air circulate through, hopefully you will have a few good frosts that will help control insect eggs that are overwintering. Remove some of the soil/potting mix and replenish with fresh potting mix and compost before replanting in spring. Add trichoderma to the soil, which is a beneficial natural disease inhibitor that feeds on soil fungi, it is available in garden centres and DIY stores. Maintain a regular spray programme, there are organic options available to control white fly, your local garden centre will be able to recommend one to you. There are yellow sticky traps that can be hung in glasshouses to attract white fly, this helps monitor populations and are available from garden centres and DIY stores. To prevent blight affecting your tomato crops next season, there are a few things you can do, such as improving ventilation to ensure good air circulation around your plants. Water plants in the morning, avoid wetting the foliage. Remove the lower leaves once the first truss of fruit has set to improve air circulation around your plants. Feed with a balanced tomato food high in potassium, avoid nitrogen rich fertilisers as this promotes soft leafy growth. Try and plant tomato varieties that are resistant to blight, and apply seaweed plant tonic to your crop every 2 weeks at a rate of 70ml per 9L watering can to ensure plants are healthy and actively growing. Lianne.