Bitch scorch is a major issue for gardeners with female dogs. It is obviously caused by female dogs urinating on grass lawns, but there is some debate about the actual chemical in dog urine that is toxic to grass. Excess ammonia, phosphorus, and/or potassium look to be the likely main factors at play. Bitch scorch is extremely unsightly and is something that dog owners need to keep on top of before it gets out of hand. Here are the seven steps to keeping a luscious lawn even when you have a dog in the garden:
- If the grass is completely dead then scarify (rake) to remove the dead leaf tissue. If it is yellow, leave it in place for now. If you do scarify, then also sprinkle on some grass seed and water it in. Without scarification the dead grass leaves will get in the way of the new growth that will follow.
- Apply Liquid Gypsum to the affected spots or apply as a blanket treatment if the issue is severe. The calcium in the Liquid Gypsum will counter the extremely high levels of ammonia and phosphorus in the dog urine that cause the grass to die off. The phosphorus will react with the calcium to form calcium phosphate, which is insoluble and so cannot get into the plant cells. Apply liberally over the affected area with a watering can; 250mL of Liquid Gypsum per 5 litres of tap water.
- Some companies sell powdered gypsum or suspension gypsum to treat bitch scorch (you will find this in products specifically designed to treat it in garden centres). However, powdered/suspension gypsum does not work instantly and does not penetrate the soil; Liquid Gypsum in contrast gets down into the soil and works on the day it is applied!
- Water the lawn in dry / hot periods. This keeps the plant growing and better able to resist the stress from urine.
- Mow to a medium/high setting on your lawn mower. Again, this keeps the plant strong. Short cut grass has much smaller root systems because the plant cannot maintain the roots due to the reduced photosynthesis from the shorter leaves.
- Mow more frequently. This prevents the stress induced by one big cut where the plant loses up to 80% of its total biomass. Imagine if you lost 80% of your weight in one go, you’d be stressed too! So mowing often helps the plant stay healthy for when it is next subjected to an undignified dollop of dog waste.
- Fertilise little and often, and for longer during the year to keep the grass vigorous and healthy. Unfertilised lawns tend to stop growing earlier in autumn, and start growing later in the spring. The addition of a plant biostimulant, such as Seaweed Extract, will also help get the grass growing faster in a cold spring, and help with resistant to stresses, such as urine.
- Aerate with spikes in the summer. Aerating the soil helps get oxygen to the roots and also helps with drainage. A healthy root system is essential for a thriving lawn. As discussed above, the healthier and faster the lawn grows, the more stress it can overcome. Do not attempt spiking if the soil is wet, this will be counter-productive and just drive more air out of the soil pores.
There is also some debate as to whether female dog urine is more toxic than male urine. In reality, both are probably equally toxic to plants, it is just that male dogs do not tend to urinate on lawns. In fact, male dogs’ urine can also cause damage to plants, but due to their behaviour, male dog urine is an issue for primarily for street trees; where it can damage the bark of sensitive trees.
