Vegetable seed sowing and watering for containers.

In a previous post I wrote about preparing your window box for vegetable growing, the layering of composts and the use of bubble wrap to help reduce your need to water in summer.

In this post let’s look at seed sowing and watering. Because you are growing in a container topped off with John Innes seed compost you have no great preparation just before you sow your seed.

For example, you have no obstacles to remove from the soil such as stones, sticks, or weeds, which when gardening in regular soil can impede the growth of young veg.

Fish blood and bone, photo / pic / image.

Vegetable seed sowing tips. Usually all I will do before sowing is apply a small pinch (1g) of fish blood and bone over the composts surface and lightly tickle this in with a small garden fork.

Available from all good garden centres fish blood and bone is a balanced plant food used to boost all-around fertility through its introduction of the 3 major plant nutrients, nitrogen 5, phosphorus 5, and potassium 6.5 (approximate balance).

To sow your vegetable seeds in a container, do so as you would normally in a ground bed. Be guided by the instructions on the seed pack regarding spacing, sowing depth, and eventual thinning, but keep the following in mind….

(1) Planting your seeds too deep is a mortal vegetable growing sin. Seeds that are buried deeper than they require may only emerge late in the season, or they may not be able to struggle up through the soil at all.

A rough rule of thumb that you can follow is that the seeds should not be covered with a layer of compost more than twice their diameter.

For example if a pea seed is an inch wide, then sow it two inches deep. Tiny seeds like those of lettuce can be just pressed down into the surface of the compost. And that brings me to point two.


Left over flooring, use it to make a tamp, photo / pic / image.

(2) Once you have sown your seed at the correct depth and your compost is back in position, you should then firm the soil. This removes excessive air pockets and prevents rain from washing away both seeds and soil together.

How would you do this? Well just seek out a small flat piece of wood that will fit inside the lip of your container, then press it down lightly onto the compost surface. Job done, then you can water lightly.

As the young vegetables grow.

As young seedlings your veggies are very vulnerable to harsh watering techniques, so be careful where you point that hose. A strong blast from a hose can break young stems or even wash the plants wholesale out of the compost.

A watering can is a much more refined watering tool for the caring gardener, causing no damage as you irrigate. Another advantage of the watering can is that as your vegetables get past the seedling stage and start to mature, then you can add water-soluble fertilisers to the water once every week or two.

Irish stock.

UK stock.

These fertilisers such as “Miracle Gro” or homemade compost/nettle tea are a great supplement, compensating for all the nutrients that are inevitably washed out through frequent watering.

Because the soil in containers tends to dry out quickly (wind & baking sun), frequent watering is vital to achieve a good crop.

If you allow your compost to dry out, then your vegetables feeder roots will be damaged. When you finally get around to watering, the vegetables energy which should be used for flowering, fruiting, or root swelling is instead diverted to grow new feeder roots, and you will have taken a setback.

Phone Home

Give your compost the finger, but not in a bad way, photo / pic / image.

So, check your window boxes daily to judge the need for water. But how do you gauge when they need water?

This is a handy one, just use your finger. Stick your finger into your containers compost; if the compost 5cm (2 inches) below the pots surface is dry, then it is time to water.

Two tips for watering.

(1) Soak the soil completely, avoiding the light sprinkling approach.

Deep watering causes roots to drive deep into the compost making them much more able to deal with future droughts. A timid little sprinkling has the reverse effect, drawing roots to the surface only to be damaged by drying winds and sunlight.

(2) Water your container veg in the morning. By doing this your plants will be less inclined to fall prey to the fungal and other diseases which thrive after an evenings watering and the mild nights that follow.

Further reading: Part 1: Window box vegetable growing for gardeners with limited space.

Part 2: Window box vegetables, What you will need & how to put it all together

More debate about this topic on our forum,
click The Irish gardeners forum.

Creative Commons License photo credit 1: SideLong

Creative Commons License photo credit: bhollar

?? Did you like this post? Yes, then click below to share it with others. ??

Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

2 Responses to “Vegetable seed sowing and watering for containers.”

  1. Window box vegetable growing for gardeners with limited space. | Says:

    [...] Vegetable seed sowing and watering for containers. [...]

  2. Window box vegetables, What you will need & how to put it all together | Says:

    [...] Vegetable seed sowing and watering for containers. [...]

Leave a Reply

 Subscribe to RSS feed.

 Subscribe to Email Alerts.

 Follow us on twitter to read allotment & gardening news from your area first.

Email your allotment news and images for inclusion on the blog to...
Garden related?
Advertise on Ireland's busiest website in the gardening niche....... Irish Gardeners forum.
Monthly Archives.