At the Millennium Seed Bank (MSB)  we grow our seedlings in the nursery. Just like human babies, young plants need a lot of care! Spring is the busiest season in the glasshouses, where thriving seedlings quickly take over any free space. It is a treat to watch these tiny plants flourish and incredibly rewarding to know that they will yield precious seeds for use in conservation.

The huge diversity in shape and size of UK seeds is reflected in their seedlings. Some are strong and seem determined to get growing right away. Others are tiny and extremely delicate, so we must adapt our approach to suit the species. A good, peat-free compost is always a must, this gives hungry plants a nutrient boost that fuels growth. Also, mixing compost with aerating beads, called perlite, helps water to drain easily. This helps to maintain a healthy environment for young roots to spread.

We all feel more awake when the clocks spring forward and days grow longer, and this shot of sunlight is just what growing seedlings need. Leaves appear green because their cells contain chlorophyll, a green pigment which enables photosynthesis. This biochemical reaction requires light to produce glucose, a plant’s power source. Without enough light leaves will actively seek more, stretching high and weakening the stem. This is bad news, as the seedling is in danger of toppling over. However, as long as the problem is understood quickly and plants are moved to brighter areas, they usually recover well.

Poor light levels were potentially problematic for a Colour in the Margins target species this year: Spreading Hedge-Parsley . Previous MSB tests showed that seeds usually take a couple of months to germinate. So, in theory, January sowing would see the first seedlings arrive in March, just as light levels begin to pick up. However, seeds rarely behave as expected and this time germination started after just twelve days!

Growing tiny plants in the gloomy early days of February presented a challenge. Sunlight reaching the nursery glasshouses was in short supply and not strong enough to sustain the seedlings. Because of this we opted to use a growth cabinet as a holding room, until natural light levels improved. Growth cabinets provide high intensity light and carefully controlled temperatures to support healthy plant growth, whatever the time of year. Although natural sunlight is still preferred, so once the seasons shifted the seedlings were moved to a glasshouse, where spring sunshine enabled the infant plants to rapidly fill their pots!

Seedlings can become ‘root-bound’ if a cramped container restricts root growth, so repotting the plants to offer a bit of extra room became a priority. Now that spring has well and truly sprung, our Spreading Hedge-Parsley Plants are (already!) filling their big pots and look more than capable of providing a large seed collection for Colour in the Margins.

It won’t be long until all of our rapidly-growing target species are flowering. After enjoying their beautiful displays, the next challenge of monitoring seed development begins. This really keeps us on our toes, so look out for our next blog, where we’ll be shedding light on the ins and outs of seed collecting!

Find out more about Colour in the Margins projects here.


Sarah Pocock

UK Native Seed Hub Assistant - MSB.

Would you like to help this incredible species? There are numerous ways in which you can:

  • Why not volunteer for Back from the Brink? Check out our events page for opportunities near you.
  • Help us to spread the word of this species, and the others we will be helping over the next 3 years, by sharing our message across our Twitter, Facebook, Instagram and YouTube pages. Follow us: @naturebftb.
  • Finally - help support the work we do across England by donating. Our impact will be greater with your help.