Vegetable beds. Photo / Gareth Carter
OPINION
We have had a sharp switch this year from winter weather to more spring-like conditions which is a great prompting to ensure that a succession of vegetable seedlings are planted and maintained if we want an ongoing harvest.
It is still very early in the spring timeline and it is important that our exuberance to plant summer vegetables does not exceed the prevailing weather conditions, particularly night temperatures. There are however plenty of hardy vegetables to be planted now.
Cabbage
Plant now in full sun in a well-drained fertile soil. Purple leaves are a sign of being short of nitrogen – feed with a sprinkle of Ican Organic Vegetable Food or Yates Dynamic Lifter.
Kale
This has become recognised as a ‘superfood’, its requirements are like other brassicas (cauliflower, broccoli). It matures in 60-70 days and can be used cooked or fresh when finely chopped into salad or coleslaw.
Broccoli
It’s an easy vegetable to grow. Plant in full sun in a well-drained fertile soil. Be wary of slugs, snails and caterpillars. Broccoli matures to its best in 40-70 days, quicker than cabbage and cauliflower. Plant 30-45cm apart. Most broccoli will continue to produce an abundance of shoots after the main head has been harvested so don’t be hasty in pulling the plants out.
Cauliflower
Plant in full sun in a well-drained fertile soil, like cabbage and broccoli, slugs, snails and caterpillars can be a problem but easily treated with slug-pellets and Yates Success. As your cauliflowers start to develop snap some outside leaves over the heart to prevent burning and discolouration from the sun.
Celery
The flavour of homegrown celery is hard to beat. Plant 20cm apart, water and feed regularly matures in 100 days
Lettuce
There are a number of varieties available including the hearting and frilly varieties which you can harvest a leaf at a time, allowing the remaining plant to keep growing. Lettuce can be grown in pots and troughs if you are limited for space, and of course in the garden. Plant in fertile well well-drained composted soil or potting mix. Space 30cm apart, water and feed regularly, good also in a glasshouse.
Spinach
Has become very popular, it grows easily like silverbeet and will be ready to start harvesting in 6-8 weeks.
Silverbeet
A very tough vegetable that requires little attention. Also in stores is a coloured selection which has stems shaded red and yellow tones. A colourful addition to the vegetable garden and often grown in the flower garden, these varieties taste the same as the traditional silverbeet.
Carrots
Best grown from seeds and sown directly into the garden. They like to grow in nitrogen-poor soil, so a good tip is to plant after a crop of lettuces or other variety that will have depleted the soil’s nitrogen levels. This is the same as with growing parsnips. Avoid using fertilisers with high nitrogen levels which will cause the carrots to fork.
There is more that can also be planted now and is available in stores in punnets including; onions, spring onions, garlic, parsley, coriander, celeriac, rocket, spinach, mizuna, Chinese cabbage (tatsoi), broccoflower, chicory and more.
Tomatoes
... and other heat-loving summer vegetables such as capsicums, chilli, courgettes, cucumber, and pumpkins are all available at garden centres now.
Many are planting these out now into glasshouses, cloches, pots and in sheltered parts of the garden where protection can be given from any late frosts and cool overnight temperatures. For those with more exposed garden situations one is best to wait for planting your first tomatoes for a week or three depending on weather conditions and soil temperatures.
Generally in Whanganui the last week of September is regarded as a safe planting time to start planting tomatoes outside.
To be successful night temperatures are best maintained above 10C. The same timing and conditions apply to growing beans and corn which are best sown directly into the garden bed where they are to grow. The most common failure with beans is from sowing too early when the soil is not warm enough.
Preparing the soil
When preparing for a vegetable garden the first step ensuring success is preparing the soil. The removal of weeds is imperative, if the area is infested with oxalis, paspalum, couch or another invasive rhizomatous spreading type weed then you will need to use a systemic weedkiller to ensure through removal of weeds.
Otherwise, you will likely have a losing battle with your vegetable garden. Many weeds will be able to be successfully cleared by hand and even dug into the soil adding to create more organic matter. If you are unsure whether the weeds you have are invasive you can bring in samples to the garden centre and check with the staff.
Feeding
Depending on the soil type the addition of a rich compost (not a cheap filler of pine bark called compost). Quality ones are the poultry-based Ican Premium Compost and Easy Earth Compost are highly recommended.
A balanced fertiliser such as Ican Organic Vegetable Food is also a great product for use prior to planting and as a side dressing later.
These products will help with both soil structure and fertility which need to be addressed regularly for a successful vegetable garden. Vegetables take a lot of nutrients from the soil so ongoing regular additions of products such as; compost, Tui Sheep Pellets and Ican Organic Vegetable Food will replace these as well as producing a more friable soil suitable for vegetable growing.
Most vegetables prefer a neutral pH to alkaline soil, ie. pH 7-8. It is recommended to dust the soil annually with garden lime to maintain the slightly alkaline soil and improve the soil structure. An alkaline soil increases the availability of many nutrients in the soil and makes them more readily available for plant uptake.
Vegetables in Pots
A great way to get vegetables growing before the weather is warm enough for outside planting is to start them off in pots. Try growing an early tomato in a pot. It can be a great way to get ahead of the game and allows you the option to move it inside if the weather turns cold.
Tui have brought out some excellent Tomato Tubs which have a water reservoir and support frame. I use these myself for cucumbers, and in the cooler months for sugar snap peas and they are excellent.
Growing vegetables in pots is great also if you are limited for space. Container vegetable growing is increasing in popularity with specialist potting mixes such as Tui Vegetable Mix for general vegetable plants, as well as specific blends such as Tui Strawberry Mix and Tui Tomato Mix.
The key to growing in pots is watering and feeding. When the plants are getting large and the roots have filled the pot, a warm day will dry these out quickly.
At this point the addition of a saucer to the bottom of the pot can be of help or simply half submerging the pot into a garden bed so it can suck water from the surrounding soil up through the drainage holes is another idea.
As the plant is limited to the nutrients in the pot fill of mix, these can be quickly exhausted. Fertilising little and often reducing the opportunity for the leaching through of nutrient give the best results.
So give it a go, growing your own vegetables is rewarding and fun!
For more gardening information visit www.springvalegardencentre.co.nz
Gareth Carter is general manager of Springvale Garden Centre.
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