Guide
Identifying and responding to crop problems
Catching problems early is the most effective intervention. Most issues follow recognisable patterns - knowing what to look for saves crops.
Start with the symptoms
Yellow leaves, holes, wilting, spots, and discolouration each point to different problems. Yellowing from the bottom up usually indicates nutrient deficiency or root stress. Yellowing in patches or across young leaves often points to disease. Holes with ragged edges suggest slugs or caterpillars; clean round holes suggest flea beetles.
Check the whole plant
Look under leaves, at the stem base, and in the soil. Aphids cluster under leaves and at growing tips. Root problems only show above ground once they are serious. Turning over a leaf takes seconds and often reveals the cause immediately.
Distinguish pest from disease
Pests leave physical traces - frass, webbing, slime trails, or the insects themselves. Diseases usually present as spots, mould, lesions, or systemic wilting with no visible creature. Knowing which you are dealing with determines the response.
Act proportionately
A few aphids on one plant does not require intervention - natural predators often control low populations. Widespread infestation or fast-spreading disease does. Remove affected leaves first, isolate badly affected plants, and only use treatments if the problem is spreading.
Record what you see
Note which crops are affected, when symptoms appeared, and what you did. This builds a picture over seasons - some problems recur at the same time each year and can be anticipated.