April brings us well into autumn, and the days are now getting shorter.
During this month, temperatures drop, winds ease off and weather may be mild, sunny and warm or damp and rainy, making it ideal for planting. While the soil is still warm, it’s a good time to plant trees, shrubs and herbs, as their roots will have a chance to take hold before winter.
Frosts are more likely this month on clear nights in valleys, high country, and inland. Weather in Hobart is cool and mild with 11-13 days of rainfall on average, with first snow appearing in mountain areas.
This is also the last chance to harvest fruit such as apples and pears (if they are ripe) before they’re damaged by frost. (To tell if an apple or pear is ripe, lift the fruit up gently in the palm of your hand, and give it a slight twist. Ripe fruit will come away easily with the stalk still attached to the fruit).
Things to Do This Month:
- Plant new trees, shrubs, climbers, annuals and perennials.
- Gather and compost autumn leaves.
- Divide overgrown perennials, collect their seeds, prune those that have finished flowering,
- Relocate evergreen shrubs (can be done either in autumn or early spring).
- Prune tall shrubs to reduce their height to better resist winter winds.
- Collect and sow seeds from berry producing trees and shrubs.
- Propagation of hardwood cuttings is done in autumn – prune off 30cm long shoots of current season’s growth, cut off the soft growing tip and the bottom end below a bud, dip end into rooting hormone. Make a ‘slit trench’ by pushing a spade into soil and rocking it back and forth. In clay soil, add some coarse sand for drainage. Put cuttings in so lower 2/3 is below the soil, and press the soil down around them. Cuttings will root and be ready to plant next autumn.
- Dig in cool season green manures that were sown in early autumn (such as rapeseed, broad beans, fenugreek, linseed, lupins, mustard, oats, subclover, and vetch) before they flower.
- Prune brambleberries after they finish fruiting – cut out the canes that fruited, and tie in the newly grown canes to the support wires on the berry trellises.
- Blackcurrants (and brambleberries) can be pruned from now till winter time.
- Continue planting garlic, strawberry runners and shallot bulbs.
- Harvest and store root crops – continue lifting beetroot and carrots and finish lifting potatoes. Leave parsnips in ground, they need some cold to taste the best.
- Cut down asparagus foliage that has turned yellow (if it wasn’t done in March) and top-dress the asparagus crowns with compost or manure.
- Cut back the tops of other perennial vegetables that are beginning to die back.
- Empty compost bins into the garden to prepare soil for next season.
Vegetables and Herbs to Grow in April (Cool & Alpine Climate)
| April Seeds to Sow and Seedlings to Plant (Cool & Alpine Climate Australia) | Sow/Plant | Harvest (weeks) |
| Beetroot | dst | 7-10 |
| Broad Beans | dst | 12-22 |
| Chives | t | 7-11 |
| Coriander (Cilantro) | dst | 4-6 |
| Corn Salad | d | 5-8 |
| Daikon | d | 8-10 |
| Endive | t | 10-11 |
| Garlic | plant cloves | 17-25 |
| Kohlrabi | t | 7-10 |
| Lettuce | dst | 8-12 |
| Mizuna | dst | 5-7 |
| Mustard Greens | dst | 5-8 |
| Pak Choy | dst | 6-11 |
| Parsley | dst | 9-19 |
| Radish | d | 5-7 |
| Rocket | d | 21-35 days |
| Shallots | d | 12-15 |
| Silverbeet (Swiss Chard) | t | 7-12 |
| Spinach | dst | 5-11 |
| Spring Onions (Bunching Onions) | dst | 6-10 |
| Swedes (Rutabaga) | t | 10-14 |
| Turnip | d | 6-9 |
Key:
d = sow seeds directly into ground
s = sow seeds into seed tray
ds = sow seeds directly into ground or seed tray
t = transplant seedlings (small plants) into larger pots or plant into ground
*= frost tender
**= sow after frost
Download printable PDF version of Gardening Calendar (Australian Cool & Alpine Climate) – April
To help improve these garden calendars, feedback and additional information from readers is greatly appreciated! Australia’s climate varies considerably, and local knowledge of when particular things need to be done in the garden are most helpful to others living in those area, so please feel free to share.