May is the last month of autumn, and the weather is sunny and dry in the tropics. In Darwin, the weather is hot and humid, with temperatures over 30°C, and it’s also the first month of the dry season, with an average rainfall of only two days for the month.
This is a time for pruning, taking cuttings for propagation, dividing perennials, planting new trees, shrubs and vines, as well as moving and relocating plants around the garden.
It’s also the time to clean up the garden, to remove all the dead and dried leaves, branches and plants, which is a great source of organic matter for mulching and composting!
Things to Do This Month:
- Continue planting new trees, shrubs, climbers, annuals and perennials.
- Continue gathering and composting autumn leaves.
- Continue planting cool season green manure crops (such as rapeseed, broad beans, fenugreek, linseed, lupins, mustard, oats, subclover, and vetch), which will be cut down and dug into the soil in spring.
- Continue collecting and sowing seeds from berry producing trees and shrubs.
- Continue lifting and dividing overgrown perennial plants.
- Continue planting garlic, strawberry runners and shallot bulbs.
- Winter pruning of deciduous trees and shrubs can be done in autumn or winter, and can begin now.
- Check citrus for galls caused by gall wasp and slice one side of galls or prune to remove.
- Cut back bamboo, and use the canes next season as plants supports or stakes in the garden.
- Repair trellises now that leaves have fallen from deciduous plants, allowing better access.
- Check tree ties, stakes and supports. Install windbreaks and tree guards around vulnerable plants.
- Relocate evergreen shrubs (can be done either in autumn and early spring).
- Lift rooted hardwood cuttings produced last autumn (the year before) and plant them out to a permanent location.
- Some perennials plants with long fleshy roots such as horseradish can be propagated by root cuttings, take root cuttings from this time in late autumn until late winter.
- Propagate rhubarb by lifting root, divide it so each piece has one or more buds and replant.
- Ponds should be cleaned of old plants, and overgrown marginal plants around the pond can be divided.
Vegetables and Herbs to Grow in May (Tropical Climate)
|May Seeds to Sow and Seedlings to Plant (Tropical Climate Australia)||Sow/Plant||Harvest (weeks)|
|Asparagus||plant crowns||2-3 years|
|Beans (Dwarf, Bush)||dst||7-10|
|French Tarragon||t||30-40 days|
|NZ Spinach (Warrigal Greens)||dst||8-10|
|Potato||plant seed potato tubers||15-20|
|Silverbeet (Swiss Chard)||dst||7-12|
|Spring Onions (Bunching Onions)||dst||6-10|
|Strawberry (seed)||s||12 months|
|Sweet Potato (Kumara)||plant crowns||15-17|
|Zucchini (Courgette, Marrow)||dst||6-9|
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 Tropical Climate) – May
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.