March growing with Cel Robertson

Flowers on allotment

Hello again! I’m Cel Robertson – a cut flower grower from North Norfolk, and I’m growing the cut flower varieties from this year’s Free Seeds campaign. I love this time of the year; with my seed trays washed, compost sieved and seed packets at the ready, I’m eager to tear those packets open and get sowing! My daily check of the seed trays to see what has germinated is never a chore, and the delight I feel when I see tiny seed leaves pushing up through the compost hasn’t diminished, despite the number of years I’ve been gardening!


March is the month when gardeners start sowing seeds in earnest. I have to remind myself not to get too carried away though, especially early in the month, as the weather can still be unpredictable, with freezing temperatures possible. Sometimes waiting just a week or so will give you better germination results, if the temperature is forecast to drop.

  • Click here for details of which seeds you can look forward to receiving when.
  • Get growing advice now, for all 12 packs of free seeds.

Glorious strawflowers

Strawflowers, or Xerochrysum, make wonderful cut flowers, fresh or dried

This month’s free seeds are Xerochrysum ‘Double Mixed’, commonly known as strawflower. The flowers have stunning papery petals and make lovely cut flowers both fresh and dried, as well as being brilliantly colourful additions to the garden border. You'll be doing your bit for wildlife too as bees love them! Strawflowers are native to Australia, so they prefer a fertile, but free-draining soil in full sun – they grow really well on my sandy-loam soil in Norfolk.

Sow with me

Cel with compost sieve
Sieve compost that you're going to sow seeds into, to remove large lumps and reduce air pockets

I'll be sowing my seeds in module trays in my polytunnel towards the end of the month. I fill the tray with sieved compost then tap it smartly on the sowing bench to knock out any air pockets and settle the compost – this will also help me see if the compost is distributed evenly across each cell. I’ll sow two to three strawflower seeds per cell and cover them very lightly with a layer of sieved vermiculite, but you could just use compost. Don’t cover the seeds entirely as a little bit of light can help them germinate.

To water, I'll stand the seed tray in a tray of water so the compost is moistened from underneath rather than being watered from above. You could cover the tray with a plastic lid so the compost doesn’t dry out too quickly. The seeds will need to be kept at 15–20°C degrees for the best germination results. With any luck, the seeds will geminate within 14–21 days.

More like this
Sowing flower seeds direct in the border
Wait until the weather warms up before sowing any seeds directly into the soil outside

If you don’t have space to start your seeds inside, you can sow them directly into beds in your garden, but it’s probably best to wait a month or so before doing this. Draw a drill into the soil and water first before sowing the seed thinly and then cover with a very light scattering of soil. Once germinated, you can thin the seedlings so you leave about 25cm between plants.

Once the seedlings appear, I’ll thin them out by removing the weakest seedlings and leave the strongest plant to grow on. The plants will need to be hardened off and then I’ll plant them out into the garden after my last frost date – your last frost date may be different to mine.

My top tips for strawflowers
  • Pinch out the leading stem of each plant when it is about 25cm high. This will help generate lots more flowering stems and produce a bushier, sturdier plant.
  • You may need to support individual plants in the border with a cane, especially if you have a windy garden!

Echium update


Last month I sowed a tray of Echium ‘Blue Bedder’ and I am delighted to report that the seeds germinated in a week! I was quite surprised; I’ve not grown echiums before and I had read that germination could be erratic. As soon as these seedlings had a set of true leaves I pricked them out of the flat seed tray into 9cm pots and left them to grow on in a cooler spot in the tunnel. Once the plants are growing well I will start to harden them off by moving them to a bench outside before planting them into my new pollinator bed in April – I'll keep you updated with their progress, I can't wait to see them flowering!


Find out what our growers are up to