Short on space?
No kitchen garden plot or allotment, but still have the ‘grá’ to grow your own food? Rest assured, you can still enjoy tasty homegrown produce from a windowsill, balcony, paved patio or rooftop as almost all vegetables will grow in containers and believe me, unlikely spaces can be softened with edible plants and can yield more than you might think.
For convenience, you can grow food close to the kitchen and tender plants can be brought indoors for protection, thus lengthening the growing season.
From classy terracotta and glazed ceramic pots to plain plastic purpose-made planters and grow bags, there is no end to the commercial options for container gardeners. However, making your own personal, funky flower and vegetable planters is a more sustainable option and can offer greater financial, environmental and creative rewards. As long as the selected container allows drainage and is sturdy enough to withhold the weight of damp soil and a mature crop, there’s no end to the possibilities for upcycling — buckets, pots, pans, colanders, wellies, boots, school bags, shopping bags, hand bags, tea pots, china cups, ceramic bowls, wheelbarrows — when it comes to creating a recycled container garden, your imagination is the only limitation.
* Used rubber-tyres are no longer advised as there are issues with toxic compounds leaching into your crops
* Hanging baskets can look great overflowing with strawberries or tomatoes.
The size of the container you choose depends on what you intend to grow and generally for vegetables, ‘the larger the pot, the better the crop’.
Salads and Mediterranean herbs are less demanding and happy in small pots, approx 10–15cm (4–6 inches) in depth and width whereas a much wider array of vegetables and shrubbier herbs need at least 20–30cm (8–12 inches) in depth and width. Taller plants look better in generous sized pots and will need staking. Remember to choose a container that will accommodate a plant’s root system and as larger plants have larger root systems, they have to be grown in bigger pots with more soil to accommodate them.
Larger containers produce stronger and more resilient plants that will have to be watered less frequently. All containers will need to have drainage holes and make sure to make these holes at least 1cm/½ in diameter and then cover with a drainage layer of pebbles, bits of broken pot or broken-up polystyrene packaging to ensure that the drainage holes don’t get blocked up with compost.
* Large containers can hold an enormous amount of potting soil and thus are very heavy. Place containers in a desired position before you fill or on a specially made plant trolley.
* If you are using a tall container like a welly, fill the bottom with pebbles rather than polystyrene or they will be top heavy and fall over.
Most garden soil is not ideal for use in containers as it tends to compact easily from constant watering. There are plenty of container-suitable composts and potting mixes on the market but for a large container garden, the expense of prepackaged may be quite high so it pays to make your own.
Mix your soil with quality all-purpose potting compost, garden compost, worm castings, or well-composted manure and add in some sand to provide the perfect growing medium — soil that is porous but yet humus and nutrient rich.
Do not skimp on the quality of soil for your container as your plants will be growing in a restricted environment and need the best. Soil brings weed seeds unlike the sterile shop bought mixes.
The growing medium should suit the crops — many herbs thrive in dry situations so will benefit from gritty, free draining soil, whereas most vegetables prefer a richer mix with plenty of organic matter. A tub of salads could get by on a bag of all purpose compost whereas a fruit tree will be in it’s container for years thus needing a much richer soil mix. A soil-less mix could be lighter and more suitable to hanging baskets and pots you intend to move.
* You will need to change the soil for annual vegetables every year but try using soil from last year’s hungry feeders to grow lighter feeding crops such as mixed leaves the following year.
* Grow over-wintering green manures in your large containers for digging back in fertility and bulky matter the following year.
Watering and drainage is by far the biggest balancing act when growing vegetables in containers. If water drains through your container garden soil like a sieve, your vegetables dry out too quickly and have to be watered constantly just to keep them alive.
But slow drainage is also harmful as plant roots do not like to live in a swamp. Pots and containers will always require more frequent watering than plants in the ground, especially if they are sitting on concrete patios in full sunlight.
As the season progresses and your plants mature, their root system will expand and require even more water. Don’t wait until you see plants wilting, check containers at least once a day, and twice on hot, dry, or windy days. Feel the soil to determine whether or not it is damp and remember to water the soil, not the foliage. If you are away a lot, consider setting up a drip emitter irrigation system.
* Leave one inch of space between the soil line and the top of the container so the soil doesn’t wash out when you water the plants.
* Pots such as terracotta are porous and will absorb additional water so it is well advised to soak them before use.
Apart from herbs and salads, crops growing in containers will require regular supplementary feeding.
A general all purpose seaweed-based feed every couple of weeks during the season works well. Like open ground crops, vegetables will benefit from specific feeds — ie, tomatoes will love a potassium rich comfrey feed while container grown leafy greens will thrive on nitrogen rich nettle feed.
* Apply liquid feeds after watering so that vital nutrients are not just washed out of the bottom of the container and lost.
* Putting a good layer of well-rotted manure in the bottom of large containers not only acts as a slow release organic fertiliser but also helps with water retention.
SELECTING VEG PLANTS FOR POTS
Seed companies are becoming aware of the rise in popularity of container growing and we are beginning to see an increase in the amount of patio vegetable seed varieties on the market. Some of these bush and compact varieties make perfect sense such as the Tumbler Tomatoes and Compact Dwarf Beans where as others such as ‘patio salads’ may be a false economy as standard varieties will only grow to the size they are allowed to and will do great in containers, and usually the seed is only a fraction of the price.
Bush varieties of plants have been bred to produce vegetables on short, sturdy plants, exactly what you want in a container vegetable garden. Small-fruited, early varieties are usually better container gardening plants than larger-fruited varieties.
In the restricted root-zone of a container, large-fruited varieties will produce only a few fruit, even in a rich potting mix. All veggies will grow in containers but my advice is to start with reliable, quick growing veg that you like to eat.
I would avoid growing vegetables that give you a one-time harvest at the end of a long season. Let’s just say home- grown onions are great, but each plant produces a single bulb at the end of 3-4 months so you have to ask if it’s worth devoting the space to them, especially when they’re cheap and easy to find in farmer’s markets and stores.
Cut and Come again salad leaves and herbs probably offer the highest return from containers as they are fast growing, compact, light feeders which will provide multiple harvests from a small space. Container gardening can be fun, simple and productive.
© Irish Examiner Ltd. All rights reserved