1 Buy plants in bulk and spend your money on small seedlings in large trays rather than on bigger individual plants. Some wholesale nurseries will even deliver to your doorstep.
2 Bury expensive shrubs in large plastic pots if containers aren't your thing. That way you can remove them from the beds when you leave – but make sure you tell your landlord about it and don't allow the buried plants to dry out.
3 Create a garden with cuttings. Many people pride themselves on lush gardens completely grown from cuttings and even certain trees, such as the hibiscus (Hibiscus syriacus) and willows (Salix), that will readily root from cuttings. Bear in mind, however, that certain new cultivars may not be cultivated by cuttings, as plant breeder's rights have been registered for these plants. This information will be prominently displayed on the label.
4 Salvage the rejects of others and plant them in the garden of your rented home. People often remove trees and shrubs for which they no longer have space and dump them on the sidewalk for the refuse collectors to take away – but virtually all large shrubs and trees can be successfully replanted, even tall poplars (Populus simonii). Transplanting is most successful if the root systems aren't too large. Fully grown Cape May and even fruit trees such as pomegranates and quinces can be moved or transplanted – provided this is done on the same day – and it helps if you prune back the tree or shrub and water it well. If you're serious about cultivating cast-offs, advertise in your local paper or use your community notice board to ask people to let you know when they're disposing of plants.
5 Divide – and multiply. Many groundcovers and perennials need to be divided and planted out in a larger area after a year or so. It's the ideal way to increase your stocks of red-hot pokers (Kniphofia), agapanthus and daylilies (Hemerocallis).
6 Sow seed – it's the cheapest option for patient gardeners. And if you're serious you can even carry empty envelopes with you and harvest seeds at the homes of family and friends. But bear in mind that shrubs are often sterile; they're cultivated that way.
7 Plant bulbs. They're slightly pricey to start with, but if you know you'll be in your rented home for a few years, simply leave them undisturbed and they'll reward you with beautiful flowers for two or three years. If you're the energetic type, carefully lift and divide them after all the leaves have died back and store them in brown paper bags over winter. All bulbs really need is water.
8 Fill your beds the smart way. Cut back on plants and mulch the empty spaces with bark, nutshells, pebbles or other organic materials. This creates the impression of full beds without emptying your pockets – and the mulch can be reused time and again.
9 Plant flowering perennial shrubs and groundcovers. It's certainly a whole lot cheaper than replacing annuals after they've stopped flowering.
10 Stick to one or two colours in each bed. Your beds will look fuller, faster that way. And don't only consider flowers for colour – coloured foliage looks good throughout the year, while many flowers bloom for only a short while.