Preparing an autumn/winter vegie garden
The first section here covers soil preparation, watering tips and site selection. With these covered, not much can go wrong! Below this section, are 6 families of vegetables and herbs with specific guidelines for each. It is worth reading the whole article to get a good overview of what is required for a successful harvest. This will particularly help with choosing the best position for each family of vegies.
1. Soil preparation
Soil preparation is everything. Soil needs to be rich in organic matter, free draining, friable and able to hold moisture well. There are 3 main types of soil: loamy, sandy, and clay. As Banyule is built on clay, we’ll concentrate on clay soil here. The best way to lighten and add nutrients to clay soil is to add gypsum (available at your local nursery) which acts as a clay breaker and provides calcium, then dig as much compost into the clay as you can. This will add nutrients, aerate the soil, improve drainage and help retain moisture. You may even want to order some bulk Vegie Mix, (a combination of loam, cow manure and mushroom compost), to add to your soil. Vegie mix is also useful if you are building raised beds or wicking beds. Clay soils in Banyule lack boron and molybdenum so add some trace elements.
Test your soil with a pH kit. These cost about $25 and last forever. You might even want to share one with friends. The pH scale is from 1 -14 with 7 being neutral. Below 7 is acidic, above 7 alkaline. Most vegies grow in the 6 -7 range but some will grow to 8 and some as low as 5.5. Generally there is a chart in the kit with the pH range for the different vegetables. If your soil is too acidic, add lime or dolomite and if too alkaline add sulphur, and both dig and water it in. It is quicker to turn acidic soil alkaline than vice versa. Mushroom compost is alkaline so this can work as an additive but too much will turn your soil too alkaline. Follow the instructions on the additive packets carefully.
I cannot stress how much lack of water impacts development. Less than 10 mm of rain any day does not count at all. All seedlings need to be well watered at least every second day until well established and then watered deeply twice a week throughout autumn – winter – spring – summer. Water on to the soil not the leaves. This may mean placing the hose underneath cabbages or cauliflower, for example. These will not benefit from rain or overhead watering due to how dense the bed will become with leaves. Plants primarily take water up through their roots so that is where you need to get water. Watering the leaves should be avoided.
3. Site selection
Some vegies need 6 – 8 hour sun a day. This is referred to as ‘full sun’. Some need 3 – 6 hours per day. If they need afternoon sun this is referred to as partial sun, if they need morning sun this is called partial shade, The darker the leaf the less sun is needed so if you need to plant in shady areas (i.e. partial shade), plant spinach, silverbeet, rainbow chard, cress, and other dark leaved plants there plus coriander and chervil which bolt quickly in the sun. For more information, go to the article ‘How much sun do vegies need?
Plant in March – April. Choose a site with partial sun.
Root vegetables need a fine tilth i.e. fine, powdery soil with all clumps broken up, and roots, sticks and stones removed so that nothing interferes with root development, It needs to be dug to a depth that is deeper than the vegetable eg an 18 cm carrot needs a depth of at least 24 cm of fine tilth. Preferably prepare to a depth of 30cm (a spade’s depth). Do not add manure as this will cause the root vegetables to split and fork.
Sow seeds direct into prepared beds at a depth of 1 – 2 cm and water well. Place a fence paling over the row and water again once the seedlings appear. The fence paling will protect the seed from being scratched out by birds but do check regularly for emerging shoots and remove the paling when that occurs. Check seed packets for depth of planting.
Water every second day while seedlings establish and then deeply twice a week until the weather cools. Note that March nowadays, is usually a very hot month (due to climate change), and watering regularly is important for root development. Through the winter water once a week deeply unless it is unseasonably hot.
Autumn root vegetables include carrot, parsnip, beetroot, radish, daikon, turnip and swede.
Plant April – May and keep well watered. Choose a position of partial shade.
Like root vegetables, leafy greens also need a fine tilth and plenty of compost but they do well also with well rotted manure which gives them plenty of nitrogen that causes leaves to grow quickly, and therefore taste better.
Water every second day till seedlings are established and then once a week, deeply.
Autumn/winter leafy greens include lettuce, rocket, mizuna, kale, mustard greens, spinach, chard and silverbeet, and Asian greens.
Plant March – May and keep well watered. Choose a site with full sun.
The onion family also needs a fine tilth, lots of compost and no manure. Weed control is important so weed well before planting, keep well weeded and mulch with sugar cane mulch. Dig 6 cm furrows, lay the seedlings in them, back fill with soil, and water and they will stand upright within 24 hours.
Water consistently as roots are shallow. Onion family includes onions, spring onions, shallots, leeks, and garlic. Garlic needs a false winter. Place whole heads in the fridge in paper bags for 40 days and plant late May.
Plant April – May and keep well watered. Choose a site with full sun.
Dig over the soil roughly with a fork, breaking up clods and aerating it. Avoid high nitrogen fertilisers such as fresh manure. Add compost and/or some very well rotted manure. Soak peas and broad beans in a diluted seaweed solution overnight before planting. Plant at a depth of 5 cm to avoid rodents eating the seed. Peas need climbing frames and broad beans need support to avoid stem breakage in the wind. Provide a form of wind break or a lattice made of strings between stakes.
Peas need the soil to be moist at all times. Water deeply once a week. During flowering and pod development water almost every day. Broad beans should be watered when planted and not again until 2 leaves have emerged. Overwatering causes germination failure. Broad beans can be watered deeply once a week if necessary, and also if they wilt, but soil only needs to be moist.
Legumes include broad beans, green peas, sugar snap peas and snow peas. Beans are frost tender and not suitable for autumn/winter planting.
Brassicas (cabbage family)
Plant April – May and keep well watered. Choose a site with partial shade.
Dig soil over roughly with a fork to open it up and aerate it. Add compost and well rotted manure. Avoid fresh manure which is too high in nitrogen and will cause leaves to develop at the expense of heads. pH needs to be 6.5 – 7.5 so test with a pH kit and if too acid add lime or dolomite a month before adding any well rotted manure. This means starting bed preparation about 6 weeks before planting.
Plant seedlings deeply i.e.bury them up to, and even including their lower leaves. This results in good root systems. Wobbly brassicas will not produce good heads. (Most people do not plant them deeply enough).
Brassicas require a lot of water. Small heads result from inadequate watering as do heads that are not firm. Rain is rarely adequate. Water twice weekly deeply throughout the winter. Place the hose beneath the leaves and directly onto soil so that the roots receive sufficient water. Do not water the leaves.
To prevent yellowing of cauliflower, fold a leaf over cauliflower head. Don’t worry if the leaf snaps.
Brassicas include broccoli, cabbage, cauliflower all of which have early, mid and late varieties, kohlrabi, Brussel sprouts, kale, and turnip and swede (but treat turnip and swede as root vegetables).
Some annual herbs bolt in summer so any time in autumn is an ideal time to plant them. This includes coriander and chervil. All perennial herbs such as the thymes, oreganos and marjorams, savouries, sage and rosemary can be planted in autumn.
Written by Robin Gale-Baker