To plant & sow in October NZ:
Vegetables - Sow Direct: brassicas, beetroot, carrot, coriander, lettuce, peas (in the cooler areas of NZ), radish, spinach, silverbeet, turnips. Sow in trays: Pumpkins, cucumbers, zucchini, corn
Flowers - Sow direct or in trays: Asters, anise hyssop, borage, calendula, cosmos, cornflowers, lavender, marigolds, nasturtiums, purple tansy, snapdragons, sunflowers, wallflowers
In warmer areas, at the end of the month, only when all risk of frost has passed and soil has warmed enough - Sow direct: beans, corn, zucchini, pumpkins. Plant out: capsicum, chilli, eggplants, tomatoes, zucchini

Labour Weekend
At the end of October it will be Labour weekend. A time when those in warmer parts of New Zealand will go out and start planting summer seedlings. The chance of a late frost has lessened (though it's definitely not ruled out) and the weather will be warming up.
However NZ weather is so unpredictable so if you're planting out your summer seedlings this month, it may pay to plant a few, but also save some for some even later planting in November and December.
Even when the weather seems warm, it doesn't mean the ground is yet.
I like to plant a few at the end of this month ONLY if my soil thermometer says it's warm enough, but I still keep many seedlings tucked away until next month.
You will find that even if there is no rogue frost and your seedlings survive fine, heat lovers like tomatoes planted early will not grow faster than those planted a month later when the ground is warmer.
At least 16 degrees Celsius is what you want for beans and corn, but it's at least 18 degrees Celsius that's best for tomatoes, other nightshades, melons and pumpkins.
Potatoes
Christmas potatoes planted in the last two months will be showing their big leafy tops and they'll need compost or mulch mounded around them. This will keep their long stalks from breaking in the wind and will stop the potatoes popping through and turning green in the sun.
This month and early next month is a good time to plant out main crop potatoes which can then happily grow until next year March when the leafy greens die back.
If you've had issues with pysllid in the past, cover your potato plants with a fine horticultural mesh so the psyllid can't reach the leaves to lay their eggs.

Prepare beds for heavy feeders
Corn and pumpkin are two prime examples of heavy feeders. They need extra compost and manure in their beds to get them to grow big and tasty. You can use this month to prepare those beds, before direct sowing the seeds or planting seedlings at the end of the month.
Add on organic matter like well-rotted manure or sheep pellets, chopped up seaweed, compost and worm castings. Cover the bed with mulch and let the worms and microbes have a feast until it's time for planting.

Beneficial Flowers
We are heading to the months where pollination is vital for our fresh produce. Let's get those bees in our garden by planting flowers wherever we can!
Borage, phacelia, lavender, poppies, lupins, sunflowers... these are all flowers bees and other beneficial insects (like those that eat aphids!) love.

Feed your berries
Homegrown berries are hard to beat. You can feed your blueberries, boysenberries, raspberries, gooseberries and strawberries with aged manure, to ensure a bumper crop.
Keep the soil for the berries consistently moist but don't over water it. Applying a thick layer of mulch will help conserve the water, especially as the weather warms, as well as keeping nutrients locked in there to feed the soil.

Fill your gaps (and your plate)
Direct sow baby turnips, radishes and beetroot anywhere you have gaps. They'll grow quickly and you can have fresh produce while you wait for your main summer crops to grow.
Start lettuce seeds off inside, a few seeds every week for a staggered harvest throughout the spring and summer. There are so many different and exciting types to try to keep colour and interest on your plate.
Slugs and snails
Keep on top of slugs and snails before they demolish your seedlings! Snail bait, beer traps or my personal favourite, late night snail hunts! Whichever method works for you.
Fashion a frame
If you're planting climbing beans, pumpkins, squash and cucumbers this year, a climbing frame may be what you need to save on space.
You can buy arches or build a frame out of wood, make one from stakes and string, an old spring bed base, a clothes horse... the possibilities are endless!

Happy gardening!
shelleyinon says
Thank you so much for all of this advice... I love how you encourage people to spray when the bees are away!
Suz says
How do you plant your potatoes? Place on ground and mulch heavily or do you bury them in soil and then mulch?
Elien says
I add a 10cm layer or so of compost, push the potatoes into that and then mulch it well but not excessively . Once the greens pop through I add another layer around them 😊