Having your garden designed and installed professionally is undoubtedly expensive; exactly how expensive depends on a great many factors. As a general rule of thumb, if you want to create an entirely new garden from scratch, you should probably expect to spend somewhere between 10% and 25% of the value of your house.

The main factors driving the actual cost are likely to be:

• the overall size of your garden, with bigger gardens generally costing more than small gardens, all other things being equal (which they never are…)

• whether your garden is sloping, with steep gardens generally being more expensive than those on a level

• the amount of hard landscaping in your new garden design, with constructed surfaces being generally more costly than planted ones

• commissioning bespoke construction of garden buildings, outdoor kitchens, pergolas, arbours etc

• including water features, with complex installations having the potential to become very expensive

• selecting luxury materials for paving, paths, walls etc

• planting large or mature specimen plants

• purchasing sculptures, artwork or luxury furniture for the garden

A good professional designer will be able to advise you on the cost impact of their design recommendations, and how to help you balance your aspirations with your budget.

If you intend to have your garden professionally designed, you should probably anticipate spending at least £75,000 before design fees.

Employing a professional garden designer will cost significantly more than using the design services of your landscaper, garden centre or gardener; because what you are buying is a completely different service. As a general rule of thumb, you should expect to pay between 12% and 20% over and above the cost of creating your new garden, with the percentage decreasing as the cost of the garden increases. This cost should cover the end-to-end design process, from initial concepts through detailed drawings and specifications, to acting as a consultant on the installation and building of the garden.

Landscapers are experts on building gardens, and those who work closely with designers are likely to understand the core principles of good design. However, most will not have professional design training, and are likely to be better placed to advise on how something should be built rather than on its function and aesthetics. Large landscaping practices may employ in house professional designers; but it is likely that their role is mainly to sell the practice’s landscaping services. Asking a landscaper to design your garden is like asking a manufacturer of cabinets or appliances to design your kitchen.

Similarly, gardeners are experts on maintaining gardens. Some may have excellent aesthetic judgement, and they will often be well placed to advise on the ease (or otherwise) of looking after a new garden. Again, however, most will not be professional designers, and it is likely that their recommendations will be strong on horticulture, but less so on other aspects of design. Asking a gardener to design your garden is like asking a chef to design your kitchen; they are experts in using the kitchen, but may design it around the way that they like to work, rather than how you want to use it.

Garden centres position themselves as one stop shops for home gardeners, offering a range of plants and materials, often with planting and installation services. Some may have in house designers, but their role is primarily to help the garden centre to sell their products, and the designs they provide are unlikely to be bespoke to your needs. Asking a garden centre to design your garden is like asking IKEA to design your kitchen.

Landscapers, gardeners, garden centres, plant nurseries and other trades in the horticultural industries bring incredibly valuable skills to the table. A good designer will be able to help you find these other professionals, and will work with them to create a garden bespoke to you.

Having your garden professionally designed is expensive, and it is understandable that you might want to find ways to save money. Doing so by cutting corners is likely to cost you far more in the long term; but if you feel confident to take on various tasks yourself, or to manage a range of different professionals, they are ways you can spend less.

A professional garden designer will usually offer an end-to-end design process, from initial concept, through detailed drawings and specifications to consulting on the actual installation of the garden. However, they will often be willing to provide only a part of these services.

For example, you may wish to ask a designer to provide you with only an initial concept; or perhaps with a masterplan for your garden, but not detailed designs. Or you may wish to prepare your own design concepts and ask your professional designer to help only with detailed drawings and planting plans. If you are confident in managing landscapers and gardeners yourself, this may be a route to saving money.

If you do decide to take on some of the design process yourself, some designers, myself included, will be willing and able to offer advice and consultancy to help you.

Creating a new garden takes time, and even once the garden is installed, you should expect to wait several years for it to look at its best; longer if you plant large numbers of trees. To some extent, you can reduce this time by increasing your budget; planting larger, more mature plants, or bringing more manpower to bear on the installation. However, even with unlimited resources, it will take time for plants to get established in your new garden.

The design process itself can be time consuming. A professional garden designer will take time to understand your needs, aspirations and preferences; and to understand the site, its character, context and conditions - before even beginning to develop concepts for your garden. However, taking this time upfront, and developing a strong brief that really resonates with you, can help to avoid iteration later in the process, saving you time, and potentially money.

If your garden is particularly large, you may prefer to spread the costs of creating it over several phases; the largest garden may take many years to come to full fruition if the owners have a strong vision and the drive to see it through. Smaller gardens, particularly those with a greater proportion of hard landscaping, may be able to be realised more quickly (though not necessarily more cheaply).

Plants take time to settle in to their new locations. Most will suffer transplant shock when they are first planted; a general rule of thumb is that the larger the plant, the greater the shock. A mature tree may take several years after planting before resuming growth; to the point that it may be overtaken by smaller trees planted at the same time. Other plants may take a year or more to grow a strong root system before performing at their best; with many perennials being said to first sleep, then creep before leaping into full growth.

A professional garden designer will be able to help you understand the likely timeframe for your specific project, and to make recommendation on how you can best balance this with your budget.