Gardening in Vancouver has its unique challenges, one of which is the effect that high rainfall has on gardens and lawns. High rainfall causes gardens to become acidic as the rains of winter gradually wash away nutrients from the landscape. The solution is to apply lime first, and manure or compost second. But be forewarned that any manure used must be well composted.
What is Lime? How will lime benefit my garden?
Lime is that powdery white substance most often used on lawns which helps to bring the pH level of your soils back from an acidic state toward a more neutral one. There are various forms of lime available, but note that both Rapid lime and Doloprite lime will have the most rapid effect in the garden. Other forms may take up to four months to be absorbed into the soil and change the pH of the soil. Rapid lime and Doloprite lime can be effective in as little as six weeks.
Where do I apply lime? And are there areas where I should not apply lime?
Lime is excellent for lawns, perennial garden beds, around deciduous trees and fruit trees. And yes, there are definitely areas that should not be given an application of lime.
Do not lime cedars, rhododendrons, azaleas, broadleaf evergreens, conifers and heathers. All these plants thrive in acidic conditions, which is why they look so good all the time in our heavy rainfall climate.
What type of manure should I use? When should it be applied?
If you are also applying lime to areas of your garden, be sure to put manure down a minimum of seven days later than the lime application. In spring there are various community organizations that sell manure for use in residential gardens. Mushroom manure is usually available and is the bi-product of horse manure that has been used to grow mushrooms. Bovine manures are available, as are pig, chicken and sheep manure, all are bi-products of our local farming industries. If you get fresh manure (clumpy, wet, visible grass strands), then this must be composted for six months before going on the garden beds.
If composted manure is available, this is your best bet. You will know it has been composted because it will have a crumbly texture. Composted manure can be added to garden beds or around trees in spring. Non-composted manure must wait until fall to be applied, after a good six months of decomposition.
What are the benefits of using well-composted manure in my garden?
Well-composted manure adds vital nutrients and micronutrients to the soil. It’s a natural way to fertilize perennial beds, fruit trees and deciduous shrubs and trees. By adding lime first, the pH of the soil is adjusted so that the soil is prepared to better absorb all the nutrients available in the manure. Compost can be used just as effectively as manure in providing nutrients to garden beds.