This post may be the most important one you read. If you read up on crab grass and the tips there for general weeding you should have grasped the various ways weeds can be spread. Now you are about to learn one of the worst ways weeds can spread. What makes it the worst, besides introducing exotic weeds you had never seen before, is that these weeds come as a result of something good.
Compost and top dressing. Applying these to your lawn without taking into account the possible work and cost you are creating for yourself is naivete. Not being able to see the seed does not mean it is not there. Seeds can last for years and though a perfect compost pile eliminates most of them it does not eliminate all. There are few perfect compost piles. Compost, commercially processed, is far better than top dirt and has fewer weeds. It is also better for your lawn. What follows are some suggestions when top dressing your lawn.
Expect there to be weeds. Different suppliers will have a different level of infestation. Even a reputable supplier with a great track record is unlikely to make promises. Bagged products are better than bulk and it is certainly more easy to test. (Not the large bags dropped by truck)
When you read what follows remember that small bags allow for more controlled testing and have not been exposed while sitting in a pile to more weeds after processing.
Test your product. If you are planning on top dressing your lawn it would be wise to take a wheel barrow or two and spread it on the edge of a shrub bed. If you have no annual bed or shrub bed to test it, then try and find somewhere other than your lawn to apply a sample. The main aim of this practical advice is that IF there are weeds in the product they can be identified and eradicated easier on your annual bed and the borders of a shrub bed than they can from the midst of your lawn.
When you are satisfied and you do apply to your lawn it is still imperative that you keep a close eye on weed growth. Be prepared to “nit pick” or what my crew has learned, “to be pernickety”. If there are strange weeds that sprout do not put off dealing with them. When they are very young they can be pulled out quite easily, not having roots long enough to bind and entwine with the existing grass. When we top dress the cost includes weekly visits for a month and bi weekly visits for the next month. Very important.
A few more general tips are simple. Do not spread the compost or manure too close to shrubs, perennials and young trees. At the trunk/ stalk is not where the nutrients are needed anyway. Weeds once mingled in the root system of the existing plants are much harder to eradicate. Lawns may be the hardest and most time consuming but a close second is weeding a perennial bed. This is why, when gardening, the base of the perennials is the most critical place to check and to keep clear of weeds. Our crew is instructed to check there first. The weeds between the plants are obvious and will eventually annoy you enough to remove them so, in a sense, they will take care of themselves. The least qualified employee would get the obvious, the best qualified knows the overall aim is the plants. There is nothing worse than grass in Day Lillies or Dandelions in a clump of Daisies. Most times the perennials have to be ripped out and the roots “purged” in order to separate the weed roots. Check the base of your plants first.
Though this article is done the suggestion to be apply product to a shrub base first in the latter paragraphs gave me an idea that perhaps is useful. Remember, slow gardening is better than reactionary impulses. It is up to you to be informed too. The idea? Create an annual bed that is empty from late fall until May.