Autumn Seed Sowing | Autumn Gardening

This week’s words of gardening wisdom (and photos) are by creative gardener and community builder, Phoebe Atkinson.
@nga_kaupeka
@growforresthill

Autumn always feels like the busiest time of the year in the garden. Your vegetable beds will be full of produce to harvest while the flower garden becomes rusty with seed heads – a signal that it is time to start your autumn seed sowing.

The to-do list may seem long — harvesting, cutting back and weeding, repotting containers and preparing new beds. But autumn is also a time of year that is full of promise, a fresh start as you plan your next year in the garden.

Seed sowing is one of the most important jobs in the autumn garden. Sowing seeds now, while the daytime temperatures and light levels are still optimal for growth, will give both your winter vegetables and hardy annual flowers the best start for springtime.

For more in depth information on what to be sowing now, jump over to our Autumn Seed Sowing Guide.
But first, below we’ve got some key seed sowing tips (and photos) by Phoebe Atkinson.
@nga_kaupeka | @growforresthill

Hardy Annuals

Such as those of us gardeners who fall into the category of hardy souls, willing to get out and potter rain or shine, so are hardy annuals named. Hardy, for their ability and indeed sometimes preference to establish and grow in cool conditions. Annuals, because they carry out their life cycle within the year. They are planted in autumn, to winter-over and produce blooms the following spring and summer. 

In my own garden (Ngā Kaupeka), many of spring and summer’s beauties – dara, nigella, calendula, matricaria – are already happily self-seeding and popping up in paths and various corners of the garden. As nature knows best, a sure sign that now is a good time to plant seed of these and other hardy annual flowers. 

The spring that is on the other side of this winter (that we can already start to feel is coming!) is the reason we are to grasp this seed sowing window while we can. The warmth of the ground, the heat still in the sun and the more frequent rain that characterises early autumn means that this time of year is second only to the height of spring in terms of growing magic.

Put a hardy annual seed in the ground now and it should burst into life, establish a good root system and then sit happily as the cold season comes and goes, giving you very strong plants and of course – thinking of spring – earlier flowers. 

Whether to sow direct or start seed in trays can seem confusing, but there are some simple reasons. 

First, some plants don’t transplant well due to a taproot or delicate root system, so are best direct sown. Poppy, nigella, ammi majus and sweetpeas are some examples that prefer to be sown directly. 

Second, some seed (e.g snapdragon, pansy) is so tiny, it is virtually like throwing it to the wind to sow it directly. Unless you have dried heads full of tiny saved seed (thank goodness, you glorious poppies!), it is only cost effective to sprinkle that precious gold dust in seed trays. 

Third, some seed needs light to germinate (strawflower, larkspur) so some care taken sowing in trays can make it easier to ensure conditions are optimum. 

Space.

Direct sowing is clearly the most effortless option. Simply clear the ground of plants and weeds, sprinkle seed, cover lightly and leave to fend for themselves. Hardy, remember.   

However this is not such a simple option for those of us who still have beds full of abundance in March and April. The dahlias, scabious and rudbeckia have weeks of glory left. You don’t want to pull them out and light requirements mean you can’t sow underneath them, so the only way to get around this is to sow in pots and then tuck them straight in the ground when at last the catharsis of clearing spent plants is done. 

At this point, resist the urge to treat them too kindly by coddling young potted seedlings indoors. This is the opposite of what they need, typically resulting in weak, leggy plants that are particularly prone to damage from pests and diseases. Instead, give them cool bright conditions as soon as they’ve germinated, placing them outdoors. The gardening version of tough love, this will give you much stronger, healthier, more resilient plants. Hardy. 

So the question remains, what about those that detest transplant but can’t find real estate in the ground yet? Spring sowing is just on the other side of winter pals. Better yet, allow those plants to go to seed in your garden next summer, letting them decide for themselves when and where they want to grow.

What to sow, and how:

Seed to sow directammi majus, dara, nigella, orlaya, poppy, spring flowering sweetpea

Seed to sow in trays, then transplantsnapdragon, pansies, strawflower, larkspur

Sow either waynasturtium, chinese forget-me-not, calendula, matricaria, rudbeckia, scabiosa, stock, viola, honeywort, foxglove (first season flowering varieties)

More seeds to sow this autumn

Sweet peas (+ sugar snap / snow peas)

Sweet peas fall into the category of hardy annuals, with a couple of things to note. 

According to sweet pea guru Keith Hammett, it’s best to sow spring-flowering types in autumn, while summer-flowering types should be sown from mid-winter in areas with mild winters, such as those found in northern New Zealand. Spring and summer types tend to produce sturdier plants with strong basal shoots that quickly take over from the primary shoot. However, both winter and spring strains perform well if sown alongside the summer types. 

The timing of flowering is influenced by the length of daylight hours, which varies by season and geographic location. Generally, summer-flowering strains require 12 hours of daylight to initiate flowering, spring-flowering strains require 11 hours, and winter-flowering strains require only 10 hours.

Sweet peas also fall into the category of hardy annuals that detest being transplanted due to a long deep tap root system so direct sowing is preferable. However I have had success planting into both root trainers and toilet rolls (half paper towel rolls even better) which allow for the length their long roots require. It is essential to monitor their growth and transplant as soon as roots show out the bottom for the above reason. 

I have found at Ngā Kaupeka, the birds like to feast on any type of pea tip during the winter months when pickings are slimmer so netting autumn sow peas is essential. Easier said than done with climbing bloomers!