Ruud Kleinpaste: Growing tip-top tomatoes

Growing tomatoes  <br />It’s great to have a go at these fruit – there are many varieties too and everybody has their favourite ones. But there are some problems that can occur, whether you’re raising them in an open garden bed or in a glasshouse/tunnel house<br />Tomato – (potato) psyllids are a nuisance interloper in NZ. They got here a few decades ago and will attack Solanaceous plants (potatoes, tomatoes, nightshades, poroporo, you name it).<br />I used to get heaps of them when growing tomatoes in Auckland but in Christchurch they seem to be prevalent only in autumn (takes longer to develop plague proportions).<br />What to look for?<br />First sign is “ill-thrift” on tomatoes; you just pick there’s something wrong. If you then look closely at the leaves you’ll find small “nymphs” – especially on newer leaves and on the underside.<br /><br />You’ll also find lots of tiny white crystals of excrement of these sap-suckers – it tastes like sugar (and it is!). Call it solid, crystalline honeydew if you like. When the sap-sucking bugs develop they turn into adult psyllids: like a small aphid with wings – often hopping away when disturbed.<br /><br />When you photograph them or look up close they are actually quite beautiful!<br /><br />Control/Prevention<br />In my Canterbury tunnel house (and in my open garden) I rarely get them now, simply because I am fanatical about pulling up nightshade weeds. I reckon the psyllids overwinter on these weeds, so removing them meticulously helps a lot to keep your patch clean.<br />Sprays with insecticides need to commence well before you see the first psyllids. It keeps their populations down too. I use neem oil if I have to spray, regular neem sprays will keep them down. Aim for the newer leaves/growth on the tomato plants.<br />I see some recommendations for Spinosad (Yates Success) and abamectin but have never used that.<br />I don’t grow potatoes but if you do, only use the early varieties (before Xmas!) so that your risk of spreading the psyllids to the summer tomatoes is