32August 26, 2009

Late August is a time when you may think that there is nothing to do in the garden. As in all things to do with gardening, if it isn’t winter, there is always something to do in the garden.


If you have bearded iris in your gardens, late August is the right time to divide the plants. This is an important thing to do for your irises. Over a period of 3 years, irises will develop many new rhizomes. The rhizomes are the sweet potato looking growth that sits on the surface of the soil. The rhizome is in many ways like a bulb. Food is stored in the rhizome. The leaves make the food that is stored in the rhizome. If too many rhizomes try to grow in an area, each one will suffer from lack of food. This will cause less flowering and make the rhizome more likely to be attacked by an insect called the iris borer. This insect lays eggs on the rhizome. The eggs hatch out and the larvae tunnel into the rhizome. The larvae spend their life eating and tunneling through the rhizome. Eventually, the larvae have riddled the rhizome with tunnels. This, of course, makes for a rhizome that struggles to survive.


When you divide the rhizomes, it is highly likely that the iris borer has infected the oldest rhizomes. These old rhizomes are the ones that are located in the center of the bed of rhizomes. These rhizomes should be discarded. Along the outer edge of the bed, you will find smaller size rhizomes. These are usually free from any attack by the borer. The newer rhizomes are the ones that you will be replanting in your garden.

Once you have the entire bed dug up, use a sharp knife to cut off the newest rhizomes. Each rhizome should have two to three leaf clusters attached to the rhizome. For ease of handling, you can cut the leaves back to about three inches above the rhizome. When you are ready to plant the new rhizomes, you should work some bulb food into the soil. You should also dust the cuts on the rhizome with bulb dust. The dust will help to prevent any rot from entering the cuts that were made when you separated the small rhizomes from the rest of the bed. The rhizome is planted with half of the rhizome above ground and half below ground. Space the rhizomes about 6-12 inches apart. Water each rhizome as needed to help them to establish new roots.

The older rhizomes should be discarded. Make a mental note to divide the irises again in three years. By next spring, you should be enjoying a great display of irises.


In late August, your tomato plants will have grown and should have produced many flowers that have turned into many tomatoes. These tomatoes will eventually ripen and even this year, with all of the early rain, you will get fresh tomatoes. Your tomato plants will continue to produce flowers and to set new tomatoes. The problem is, the flowers that set now will not have enough time to produce ripe tomatoes before the frost hits. You should be removing any new flower clusters to prevent them from forming new tomatoes. This will allow the tomato plant to use all of its energy to ripen the tomatoes that are already on the plant.


As your tomato plants try to ripen all of those green tomatoes, they will need a lot of potassium to do this task. Potassium is the third number that you will find on the fertilizer package. The potassium level should be relatively higher than the first number on the package. The tomato plants should be fertilized on a regular schedule right up to the time of the first frost. This will allow your tomato plants to have the potassium that they need to ripen all of those green tomatoes.


Well, that’s all for this week. I’ll talk to you again next week.

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