December Planting Guidance

Three easy steps to get your December box planted up

Click here for a Step-By-Step Video Guide:

December Planting Guide – Sweet Peas, Christmas Tree and Microgreens

 

Step One - Planting Sweet Peas for a Summer Display

December is a great time to sow sweet peas.  You’ll get flowers earlier than if you wait to sow in March and the plants will be stronger with better root systems.  Here’s what to do:

1. Preparing Pots and Compost

• Use seed compost or a good multi‑purpose compost
• Choose 9cm pots, toilet roll tubes, or root trainers
• Fill the pots right to the top, level off, and gently press the surface flat
• Water thoroughly so moisture reaches all the way through

2. Helping Seeds Germinate

• Sweet pea seeds have a thick coat, which makes them slow to germinate.
• Some guidance suggests soaking, but I find I get more consistent germination by roughening up the seedcoat with sandpaper or an emery board.  Or you can nick the seedcoat with a knife.  These are high quality seeds, so if you just sow them they should still germinate well.

3. Sowing the Seeds

• Place 2 seeds per loo roll or pot.
• Position them on the surface, then press down to about 1cm deep, spacing seeds roughly 1cm apart.
• Smooth the compost lightly back over the top of them.
• Label each pot clearly.

4. Early Growth

• Keep pots on a bright but cool windowsill, a cold-frame, or even against a sunny outdoor wall.  Sweet peas need as much sunlight as possible, especially in these dark winter months, to germinate strongly but they do not need too much heat.
• Germination usually takes 1–2 weeks.
• After another 2–3 weeks (around 5 weeks total), insert a small cane/stick and tie in seedlings.
• Pinch out the top at the 3‑leaf stage to encourage bushier growth.

5. Potting On

• If you've sown the sweet peas indoors, pop them outside in their pots/loo rolls as soon as they start to germinate.  Too much heat will lead to leggy growth as they reach for the light.  Sweet peas are tough, but protect them from excess wet.  A cold frame is ideal for hardening off if you have one.  For those of us who don’t, pop them against a sunny wall of your house, on a shelf if you have one.  They’ll get some shelter and will be protected from the worst of the rain.
• Once roots appear at the bottom of the loo roll or pot, move plants into bigger pots.  Relabel and water as needed.  Deep, narrow pots are the best as sweet peas want to stretch their roots downwards but don’t need to have lots of room to spread their roots out.  But use what you’ve got and you can skip this stage without too much impact.
• If both seeds have sprouted in a pot, keep both, they will happily grow together and don’t need to be thinned out.

6. Planting Out

• In March or April, they can be planted directly into their final position outdoors.  They need plenty of sunlight and will need supporting with canes or netting.  For the very best sweet peas, grow them against an upright support (e.g. a mesh fence).  But they look beautiful on a teepee of canes.  If you don’t have any beds or borders, you will still get nice flowers if you move them into a large pot or bucket, they just won’t grow as tall.

 

 

Step Two - Grow Your Own Christmas Tree

 This is a compact and slow-growing tree which stays manageable in size for many years, making it perfect for pots so you can bring it in each year for Christmas.  It has a naturally symmetrical shape and even as a young tree, it tends to form a neat, conical silhouette - no pruning required to get that classic Christmas tree look.  Its upright, violet-blue cones appear when it’s about 3 or 4 years old and add a magical touch, even before the tree is big enough to hang ornaments.  Plus, it’s hardy and well-suited to UK gardens: it tolerates cold and wind.  Here’s how to get started:

1. Soak seed

• Soak seeds in water for 24 hours

2. Cold period

• Drain all water and place seeds in a freezer bag and put in the fridge for 6-8 weeks.  During this time seeds must be moist, not dry or wet.

3. Preparing Pots and Compost

• Use seed compost or a good multi‑purpose compost
• Choose 9cm pots
• Fill the pots right to the top, level off, and gently press the surface flat
• Water thoroughly so moisture reaches all the way through

 4. Sowing the seeds

• Remove seeds from fridge and surface sow one seed per pot.  Cover with a fine layer of vermiculite.  If you don’t have vermiculite, use a fine layer of horticultural grit or just more seed compost.  

5. Early Growth

• Keep pots on a bright windowsill or pop them in a sunny, sheltered spot outdoors.
• Germination usually takes a few weeks and generally not all seeds germinate.

6. Potting On

• The seedlings can stay in the same pot for a year until next spring.

 

Step Three - Create Sophisticated (and Super-Healthy) Platters with Homegrown Microgreens

I’m going to come clean and admit that I’m fairly new to the world of microgreens.  If you haven’t come across them before, they’re nutrient-packed little plants that garnish many a Michelin starred chef’s plate.  If you search up how to grow them, it can appear that you need a special kit (and I’m sure those kits are great) or that the seeds require special treatment, like overhead lights.  But after experimenting with different varieties and methods, I’ve realised they behave just like any other seeds or seedlings, (which sounds obvious now I say it).  By applying all my familiar principles, I’ve had the best results.  So, here are my top tips on how to grow them:

1. Preparing Pots and Compost

• Use seed compost – it gives the seedlings a little bit of nutrition and it’s fine so it creates a nice, flat surface, easy to cut them without getting compost in your dinner
• I’ve had the best results with old fruit containers (the kind of thing you buy your blueberries in).  They have holes in the bottom and I’ve discovered that watering from underneath works better than trying to gauge how much to water and spraying with water works well too.  There are specialist microgreen trays which may be even better. 
• Put a thin layer (about 1-2cm / ½”) of seed compost in the trays.  Level off, and gently press the surface flat
• Water by putting the trays into a bigger, waterproof tray or plastic container with some water in it.  Leave them there for a few minutes, then when you take them out the compost will be nice and moist.

2. Sowing the Seeds

• Pour a layer of seeds onto the compost, they can be very close together, much closer than you would normally sow seeds
• No need to cover them with a further layer of compost

3. Dark Stage

• Stack the containers on top of each other – the seeds need a bit of pressure on them to germinate
• Put the containers on a waterproof tray or shallow container
• Put something on the top to put some pressure on the top container, this could be another empty container with a can of beans on it.
• Place them in a cupboard or somewhere dark.
• Check them every day to see if they’re germinating and to check the compost is still moist.
• After about 5-7 days they will have a root reaching down from each seed and pale yellow coloured sprouts coming out of the tops.  Note that the roots have ‘root hairs’ which look a lot like mould so look carefully at them and make sure you don’t throw good seeds away thinking they’re mouldy.

4. Light Stage

• Once you have strong sprouts about 2cm tall, move the tray onto a bright windowsill.
• Different seeds may reach this stage at different times.  It will likely be peas first, followed by ruby chard, followed by corn salad.
• Keep the compost moist using the same watering technique from Step 1 when needed.  Or you can mist them with water.

5. Harvesting

• When the seedlings are about 7cm (3”) tall, they are ready to eat.  This only takes 2-3 weeks.
• Gently lift them out of their container and snip them just above the soil line with scissors.  The seeds are organic and untreated so you don’t need to wash them; they are ready to garnish your meals, add to salads or lightly fry.