Pots of Planting – More of the Gardening Course

What with Easter, the play and the trials of rural broadband, we haven’t been able to post reports about our ongoing Gardening Course as it happened, so here are three weeks of gardening notes in one post. Put the kettle on, make tea and settle down for a read.

Richard planting up. Note the big tub of premixed planting medium.

Before you start

Planting medium: If you are making up lots of hanging baskets or pots, get a large flexible plastic bucket (about 42 litre capacity) and empty half a bag of compost into it. Add some sharp sand (a litre sized yoghurt pot is a good measure) and a few handfuls of slow release fertiliser and mix well. Water the compost and leave overnight. Don’t forget to wear gloves when handing compost.

Plants: Stand the plants in a little water overnight. This will give them a good drink and will make it easier to take them out of the trays/pots when you start planting.

Pots:  If your pots don’t have holes in them, you’ll need to make some. Drill holes at intervals around the side of the pot, about one or two inches from the base. This will give you a bit of a reservoir – enough to last a week without watering.

Types of Containers

A bag of spuds

You can buy Potato bags or use a ‘bag for life’. It needs to be about 15” square and 20” high. Half fill the bag with compost and sharp sand and plant a potato two inches down in each corner. You don’t need to chit ‘certified seed’ potatoes. A little hydrated lime added to the compost will deter slugs. (If you’re planting potatoes outdoors, sprinkle hydrated lime into the trench and put the potatoes directly onto tit, then cover with soil. If you have problems with wire worm in your soil, avoid white potatoes – try Golden wonder instead.

When the potato shoots reach two inches high, earth them up by adding more compost, till it almost covers the heaves. Repeat this till the shoots reach the top of the bags. You can harvest the potatoes once the flowers have faded.

If you want to check on the progress of the bag Richard made for us, it’s in the Brightsparks garden and the children are looking after it.

Hanging baskets

Line the hanging basket frame with a plastic bag (cut the seam off the bottom, open out and cut to size). Fill with compost with some sharp sand mixed in. Make four or five small holes evenly around the side basket for drainage and plant up with a centrepiece and four trailing plants – and don’t forget you can use Tumbler tomatoes as a trailing plant – and sprinkle in a handful of slow release fertiliser. Trim the liner, leaving an overlap of about an inch. You will need to water the basket regularly. Keep it indoors at night until all danger of frost has passed (around 30th May). By the time it goes out full time, the plants will have grown to obscure the liner completely. When watering hanging basket, make sure you get the pipe of the hose/watering can close to the soil.

Pots for summer colour

Fill your pot to the brim and put in a tall centrepiece (we used antirrhinums and fuchsias) and four smaller plants (we used a mix of mimulus (monkey flower), tagetes (marigolds), pansies, violas and candytuft) at 3, 6, 9 and 12 o’clock – if you imagine the top of the pot as a clock face. If you are using a rectangular pot, put the tallest plant in the middle and the smaller ones to each side. The pots are for summer only, so you can go wild with colours –clashing or harmonising, cool or hot colours, monochrome or rainbow.  The pots can go out now although if a frost is forecast you should take them in or cover them with some sheets of newspaper.

Deadhead your pots and baskets regularly to ensure the plant keeps pumping out flowers (unless you have planted vegetables, in which case you should leave the flowers to turn into seed (beans and peas) or fruit (tomatoes).

Pots for graves or areas that won’t get daily attention

Use heather as a centrepiece – they’re slow growing and have a long flowering season. Use violas around the edge.

Grow beds

If you have space, try grow beds. These are squares or rectangles rectangular frames of wood, set down on a weed resistant membrane and filled with a top soil, compost and sharp sand mix. Three beds will enable you to rotate crops. Richard gave us a hand drawn plan which we’ve tried to reproduce here.

The beds should be a minimum of nine inches high; for potatoes you’ll need twenty inches.

General advice

Richard dots his instruction with masses of good advice – here are a whole pile of them.

  • When grouping posts, use pots of different sizes and heights to make a more interesting display.
  • Put white and blue arrangements near the house, and more colourful pots near the road.
  • You can use a small shrub as the centrepiece for a large pot, but you’ll need to move it out to the garden once it grows too big for the pot.
  • Plan for a LARGE pot. The skimmia can be transplanted to the garden after a season or two.

  • Stand terracotta pots on wooden skids in winter to stop the frost coming up from the ground, or make small concrete feet using a three inch flower pot as a mould.
  • When buying plants for your pots, always check the roots – white roots are a good indicator of plant health; brown roots mean the plant has started to die.
  • You will need to feed your potted plants: a handful of slow release fertiliser sprinkled in as you are potting up will last for five months.
  • To deter whitefly and greenfly, crush some cloves of garlic and soak them overnight in a pint of water. Add this (once you have strained the garlic out) to your watering can and it will keep the bugs at bay.
  • When putting a cane wigwam in a pot (for growing beans or peas), drill two small holes about an inch below the top of the pot and thread a cable tie through them. Slip the cane through the cable tie on the inside of the pot. This will hold the cable tie firmly against the side of the pot so it doesn’t move around and disturb the developing roots.
  • You can use runner beans and peas as the ‘tall’ element of a pot – the red (beans) and white (peas) flowers are pretty enough to work, and you can harvest them at the end of the summer. Underplant with scallions, radishes, or baby lettuces to harvest while the beans are growing.
  • Turn your pots through 180° each week to ensure even growth all around.
  • Tagetes: these are a great greenfly/whitefly deterrent. You can plant them around roses, dotted around vegetables in the vegetable bed, or in pots at the door to the polytunnel.


Once again, our thanks to GRETB for funding this course:

1 comment

  1. Lovely post. Well done. Nice course too!

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