Gardening: Time to start planting seeds for summer veges and flowers

It's a good time to start sowing seeds indoors for planting out later.

The advance of spring has progressed further this week; despite the cold snap the early flowering cherry tree varieties Campanulata Felix Jury and Jim's Delight are now in full bloom.

With spring getting closer, it is time to start the sowing of seeds indoors of summer growing vegetable and flower plants.

For those who are keen to save money on their gardens, then growing some of your vegetable plants from seed is a good place to start. Most seeds take 14 days to germinate, then another 14 days to get to the transplanting stage which, if sown over the next week, will take us to mid-September.

If these are then transplanted into individual pots and grown on for another three weeks, then they will be ready for planting out into the garden around mid-October. This is the traditional time for planting out "cold sensitive" seedlings in Whanganui when the risk of late frost has passed and both day and night temperatures are rising.

Raising plants successfully from seed is a good way to get many plants cheaply. It is also very rewarding to go through the stages from choosing what you want to grow, to choosing what to grow them in - direct into the soil or into some type of container. Then pricking them out into larger pots and finally into your own garden. The whole adventure continues as you grow them to flowering or harvest.

Some of the flower seeds that can be sown now include petunias, impatiens (busy lizzies), bedding begonias and lobelia.

Some of the vegetable seeds that can be sown now include tomato, capsicum, eggplant, zucchini, cucumber, lettuce, pumpkin, watermelon and cold-sensitive herbs, such as basil, can also be started off in the same way.

Here are some tips for being successful at growing plants from seeds.

Firstly, reading the packet is a good start, but if you're taking the time to read this article then you will probably also read the seed packet.

If you are sowing cold-sensitive plants like those mentioned above, then they need to be sown indoors in pots or trays. The tray should be filled with a specialty seed raising mix such as Tui Seed Raising Mix. These are blended to ensure the right water holding capacity, fertiliser requirement and will often contain a fungicide which helps prevent seedlings dying after they have germinated.

A mistake sometimes made is to use garden soil in trays. Garden soil tends to retain too much moisture as it doesn't escape out the bottom of the tray/pot. The water then fills up the air gaps in the soil which the roots need to breathe. The seedlings then can effectively suffocate and die. In a garden situation, the soil is generally much deeper and thus water can drain away from where the roots would be growing.

Seeds should be sprinkled evenly on top of the seed raising mix and then covered lightly with more seed raising mix. The depth of this will be specified on the back of the packet. A general rule is to cover the seed with an amount of seed raising mix that is twice the diameter of the seed.

Next, lightly firm the mix to ensure direct contact of the seed with the mix which holds moisture and nutrients. Then water gently to thoroughly moisten the soil without washing the seeds away. Cover the tray with newspaper and place in a warm location.

Check daily that the mix has not dried out and to see if any seedlings have germinated. As soon as you see seedlings coming through, remove the newspaper and ensure they are in a light position. It is at this stage that many people go wrong; seedlings left in a position near a window but not rotated regularly can become "drawn". This means the seedlings have elongated or stretched as they crave more light than they are receiving. The result of this is a weak plant that will not transplant well into the garden at a later stage. As soon as seedlings have a second set of leaves, they should be carefully transplanted (pricked out) into individual pots.

Plastic pots or yogurt pottles with holes drilled in them can be used. Peat pots are great to use as they are fully biodegradable so when it comes to planting into the garden they go in pot and all, meaning zero root disturbance and no setback in plant growth will occur. Egg cartons can also be used to the same effect.

Once potted individually, seedlings should be grown on until they are about 15-20cm high and all danger of frost has passed. Once we are into mid-September, seedlings should be gradually hardened off; bringing them outside for a few hours a day will allow them to acclimatise.

Many seeds, such as beans, carrots, radishes and corn, should be sown straight into the garden. You need to ensure the weather will be warm enough for these crops since they will be exposed to the elements from the moment they are planted. Carrots and radishes can be planted now but corn and beans are best sown in the garden from October to December.

When sowing seeds in the garden, soil preparation needs to be the first consideration. Soil needs to be dug over and all clods broken down finely. Next, water the soil and then make a shallow groove along which the seeds should be sprinkled, lightly covered with soil and then water again. Marking each end of a row with stakes will help ensure you remember where you have planted your seeds. Watch out for cats and birds - cats sometimes presume that the finely-worked soil is a litter box and birds presume it is an easy place to shop for worms. Sometimes some bird netting, secured loosely with a stake on each corner, can be a necessary deterrent.

An exceptional range of seeds that we promote in our store is called Chefs Best, distributed by Ican. Ican brand has been developed by a group of independent garden centres with the aim to put quality and value first, addressing the issue that we are in an age where price is often pushed lower at the compromise of quality.

Garden experts have carried out extensive trials, and sought advice from vegetable seed specialists in New Zealand and internationally, to find the very best varieties for the New Zealand home gardener. The group of independent garden centres has chosen 15 of the very best vegetable varieties.

The seeds to plant now direct into the garden include:

Broad bean: Mr Green Seed - broad beans that look and taste good. They remain green after cooking.

Beetroot: Red Lightning - strong vigorous hybrid, upright, early maturing, deep red and tender; very uniform.

Carrot: Europa - best carrot available. Fast, strong germination, vigorous, resistance to alternaria and bolting. Rates very high for taste.

Lettuce: Trendsetter - this cos type has become popular for modern salads. Easy to grow, space saving, green crisp hearts, early maturing and holds well. Resistance to downy mildew, sclerotinia and aphids.

Leek: Baby - fast growing, ready to eat in eight weeks from planting out. Best harvested when finger thickness. Can be close planted to save space.

Parsnip: Trafalgar - strong, vigorous germination and rapid growth. Long straight parsnip with good canker resistance. The best home garden parsnip yet developed.

Peas: Magic - dark green pods on vigorous, high yielding plants. Good resistance to fusarium and powdery mildew means you keep on picking to the last pod produced.

Radish: Olympus - vigorous consistent variety, medium-large round. Pleasant taste. Fast maturing and disease resistant. Best radish available.

Spinach: Nutriplus - vigorous hybrid, highly nutritious variety. Strong germination and fast maturing. Resistance to downy mildew. Very consistent.

The ones to sow in trays indoors for planting out at the end of September are:

Tomato: Flavoursome - a taste sensation. Early maturing, medium size fruits. Excellent resistance to virus and soil fungus diseases. Keeps well.

Pumpkin: Dry Delight - dry with superb flavour. Vigorous heavy cropper of uniform large fruit with a sweet nutty taste. Best buttercup variety available.

Cucumber: Prolific Mini - prolific producer of small 10cm long fruit, starting earlier than other varieties and goes on producing for months. Shiny smooth skin on an early maturing cucumber with intense taste. Great in containers. Outstanding variety.

Dwarf bean: Supreme - best dwarf green bean available. High yield of fleshy, very tasty, straight 14cm long beans. High disease resistance. Preferred by chefs for cooking whole. Each sowing produces over 2-3 weeks; therefore sow at 2-3 weekly intervals for continuous supply. Harvest 7-8 weeks from sowing.

Courgette: Leader - an upright but compact grower, producing copious quantities of easy-to-pick, shiny, dark green courgettes. Excellent virus and powdery mildew resistance. The best variety available.

If you have not grown anything from seed before then why not give it a go?

• Gareth Carter is general manager of Springvale Garden Centre.