Getting the most out of your crop

TOMATO SEASON: Fresh, ripe cherry tomatoes like these don't just happen, as tomato plants are prone to pest and disease problems over summer that can decimate a crop. File picture

Tomatoes can be prone to a variety of pests, diseases and problems during summer. Here are Yates's top tips for keeping your tomatoes healthy and productive:

* Aphids and tomato fruitworm (caterpillars) are two of the most common tomato insect pests. To protect tomatoes from damage, spray tomato plants every seven-14 days with Yates Mavrik Gun Insect and Mite Spray.

* Tomato potato psyllid control — this psyllid is a tiny sap-sucking insect that can cause leaves to curl and yellow, flowers to fall, fruit to be small and misshapen and plants to be stunted. Tomato potato psyllid can also transfer a bacterial disease to plants which severely reduces fruit yields. Tomato potato psyllid can be controlled by spraying tomato plants every seven-14 days with Yates Mavrik Gun Insect and Mite Spray.

* Powdery mildew and blight control — during summer tomatoes are often affected by diseases like powdery mildew and blight. Yates Nature's Way Fungus Spray contains a combination of copper and sulphur fungicides to control common tomato diseases. Thoroughly spray tomato plants every 10-14 days to keep diseases under control.

* Prevent blossom end rot — keep watering tomato plants thoroughly to ensure the soil is consistently moist. Inadequate or irregular watering, which contributes to calcium deficiency, can predispose tomato fruit to develop a condition called blossom end rot. An application of Yates Hydrangea Pinking Liquid Lime & Dolomite can help reduce the incidence of blossom end rot by supplying plants with calcium.

Potatoes are a delicious and productive vege to grow at home and can even be grown in pots. Seed potatoes planted during late winter and spring will be growing strongly during summer. Here's what you can do during summer to promote the best possible spud harvest:

* As green shoots emerge, cover with a 15cm layer of mulch such as lucerne hay or pea straw (or alternatively, shovel soil over them), and a sprinkling of blood and bone. The mulch layer encourages the shoots to grow taller, which provides more opportunities for the potatoes to develop along the stem. It also protects the potato tubers from sunlight, which turns potatoes green and inedible.

* Water the plants if the soil and mulch feels dry.

* Each time new shoots emerge through the mulch, apply another 15cm layer of mulch and more blood and bone.

* It takes around four months for potatoes to fully mature, however impatient gardeners can harvest some tender baby potatoes a little earlier. Gently dig around the root zone of the potato plant (a technique called bandicooting) and feel for the little spuds.

Potato insect watch: keep an eye out for sap sucking aphids and mites, which can damage and distort potato foliage. Regular sprays of Yates Nature's Way Natrasoap Vege Insect Gun on both the upper and lower leaf surfaces, will help keep aphids and mites under control. It's certified for use in organic gardening so is ideal for gardeners wanting to use organic methods of insect pest control.

Boysenberries are a delicious type of “brambleberry” with rich dark purple fruit that have a sweet and slightly tart taste, resembling a combination of raspberries and blackberries. They're rich in vitamins C and K as well as being a good source of dietary fibre.

Boysenberries (Rubus ursinus x idaeus) produce soft and juicy fruit in early to mid summer, which can be used in desserts, crumbles, cakes, ice cream and drinks as well as turned into richly-coloured jams. Of course they're also delectable fresh and you might find that not many berries make it back into the house. They are ideal for growing in backyards and make an extra special treat just for home gardeners, as they're hard to find in supermarkets as the fruit don't transport or store well.

Boysenberries prefer a slightly acidic, moist, rich soil and perform best in a full sun position in cool to warm temperate zones. Growing on canes up to 2m tall, an added bonus of boysenberries is their pretty, white bee-attracting flowers in mid to late spring.

To make maintenance easier (and promote a better harvest), boysenberry canes can be trained up between two wires on a T-shaped trellis. During winter, while the boysenberry plant is leafless, cut back to ground level the canes that have borne fruit, leaving fresh, newer canes to grow and provide fruit next summer. Do this each year to avoid the canes getting messy and out of control, and encourage the best possible berry yield.

Also pull out any suckers that have emerged out of your planned boysenberry patch. A word of caution is that boysenberries produce thorns, so a good thick pair of gloves and long handled pruners can really help!

Bare-rooted boysenberry canes are often planted while they're dormant during winter, however potted plants are also available at other times of the year.

Before planting, improve the soil with a concentrated source of rich organic matter like blood and bone, then reapply around the root zone every eight weeks from spring to early autumn to promote lots of healthy cane growth, a strong root system and encourage masses of plump, juicy berries.

Fruit protection tip: birds will enjoy boysenberries as much as you, so some bird netting may be required to protect your developing crop.