HI, how can I remedy yellowing leaves on my healthy looking lemon tree?

Hi Mavis, check out the Tui website garden questions page for more information on yellow leaves on citrus here. This is common with a change of season, especially if autumn has been hot and dry and it is the lower leaves that are yellowing, not new growth. Maintain consistent watering, as the weather cools, reduce watering, for established trees in the garden water once or twice a week, for plants in pots and containers it could be 2-3 times a week. Mulch around plants to help conserve soil moisture and replenish organic matter back into the soil. Look for signs of insect pests on the underside of the leaves, white fly are prevalent at this time of year, as are mites and other sucking insects. Control using a suitable insecticide spray, your local garden centre will be able to advise you. Citrus can be fed in late summer, early autumn with a specialty citrus fertiliser such as Tui Citrus food to replenish the soil with nutrients that have been used up by the plant in the growing season. If your plant is in a pot feed with Tui Enrich Fruit, Citrus, Tree & Shrub controlled release fertiliser. If you are in a frost prone area feed plants earlier in autumn rather than later so that the new growth that comes away has time to harden off before winter and does not get frosted. Feed again in early spring. If there aren't too many yellow leaves, remove them and dispose of in the rubbish and not the compost just incase there are any insect pests present. A dose of Epsom Salts, which is a source of magnesium, can help remedy yellow leaves on citrus, but if it is only a few lower yellowing leaves a balanced fertiliser will be more suitable. Lianne