Today is dedicated to the Irish people, their heritage and their wonderful country. Very few countries have a plant that refers directly to them as the Shamrock does to Ireland. Can you envision the green landscape of the Emerald Isle on St. Patrick's Day this Saturday? Irish or not, many of us wear the green on St Patrick's Day and celebrate with a pot of Shamrocks growing on our window sill. Have you ever wondered why the Shamrock is so important to the Irish people and how it became so famous a plant?

Well...it all began with a 3-leaf clover--not the 4 leaves that many of us think as being lucky. St. Patrick came to Ireland as a missionary to teach its people about the Catholic religion and used the Shamrock as a way to demonstrate the principle of the Trinity. The three leaves represented the Father, the Son and the Holy Ghost united on a single stem. For this reason alone, a true Shamrock has 3 leaves and Irish history makes this quite clear. The term Shamrock is derived from the Irish word "seamrog" which translates to "little clover plant." In horticulture there are over 900 species of these plants, some grown from seed and some from bulbs and some of these plants are annual while others are perennial in our garden.

If you still think that the Shamrock has 4 leaflets, look at the tale wing of Aer Lingus Airlines (Ireland's National Airlines); it has 3 leaflets. And if you're from New England or a big Basketball fan, look at the Boston Celtics Logo--the Shamrock has only 3 leaflets. If you have your heart set on the 4-leaf clover, start looking as soon as the clover begins to grow in your lawn--you will need lots of luck to find one. The National Botanical Garden in Dublin, Ireland revealed that when the Irish people wear the Shamrock it usually comes from the white clover, red clover, hop clover or a clover-like plant called Black Medick. All are members of the Pea family. If the ground is still cold where you live, and you want to see a 4-leaf clover look at the box of Lucky Charms cereal for the 4-leaf clover on it. Or see the picture we put to the right.

Another family of plants is the Oxalis family; they closely resemble the Clover family. They are also sold as Shamrocks for St Patrick's Day because of their wonderful foliage with many shapes, colors and sizes of the leaf. The Oxalis family also has wonderful flowers in many beautiful colors. Oxalis originated from South Africa and Central America, and was quickly adopted by gardeners because it was easy to grow as a bulb plant. Most Oxalis plants are not winter hardy outdoors but will overwinter in a pot of soil in your basement very easily.

Here is all you have to do to grow these wonderful bulbs in pots in your home. Oxalis bulbs will be available in the fall and again in the spring where bulbs are sold at your local garden center. The bulbs are small--about the size of a lima bean seed--so plant 5 to 7 bulbs to a 4 to 6 inch pot. Use a good potting soil like Black Gold Organic Potting soil, as these bulbs prefer a rich well-drained soil that has been fortified with organic matter and contains no clay. Cover the bulbs with 2 inches of potting soil and keep them moist at all times. Like all foliage plants, fertilize monthly--especially when the are in bloom. The flowers have 5 petals; they resemble a trumpet and develop in clusters on long stems that grow above the foliage. The flowers will last on the plant for 4 to 8 weeks or more, depending on the variety; most have no fragrance.

These are some of the varieties available this week at your local greenhouse or florist:

Oxalis rubra:
This will grow to 16 inches tall and will look great in window boxes or planters. The plant has 3 leaflets that are medium green in color and hairy on the underside. The plant will bloom all summer with red to pink flowers. After first frost, dig up and pot to store in your basement for next year.

Oxalis 'Iron Cross:'
The plant will grow under a foot tall and has a cross-shaped brown spot on the foliage that is deep green in color. The flowers are red, and this plant is best kept in a container.

Oxalis triangularis:
My favorite because of the dark purple leaves that grow large--each leaflet is over an inch in diameter. The plant will have white, pink and violet flowers on it at the same time. The foliage is wonderful when used as a houseplant or when mixed in planters for contrasting foliage colors. It can also be dug up in the fall, repotted and stored in the basement for the winter. Bring it up in January and place the pot in a sunny window and water well. In just a few days, new foliage will develop and the fun begins all over.

Oxalis triangularis papilionacea:
Nice light green foliage and large leaves like the purple variety; this plant has deep pink flowers that look great against the foliage. Treat and care for just like the purple leaf type.

Oxalis triangularis papilionacea regnellii:
Nice deep green large foliage like the above two, but this plant has large clusters of bright white and very showy flowers. Flowers all summer long and is hardier but I suggest that you treat like the other two varieties during the winter. Great potted plant for containers with nice foliage to enjoy.

Now let's talk about the common Shamrocks--or clover. The plants are grown by seed and are also sold for St Patrick's Day in pots. The flowers are different from the Oxalis, as each flower is more rounded in shape and made up of many small single flower petals. The flowers grow an inch in diameter or smaller and have a bit of fragrance. The flowers form during the early summer and are loved by honeybees and butterflies. The plants are winter-hardy and can be very aggressive when they show up in your lawn. The plant spreads with both underground stems and seeds from the flowers. The plant grows very flat and close to the ground--often pushing down the grass plant in your lawn and smothering it. The foliage is medium to dark green with 3 leaflets (occasionally 4 for you 4 leaf clover fans). Makes a great pastime for the kids to see if they can find one in the lawn.

Clover is in the legume family or pea family and has the ability to pull nitrogen out of the air and place it in your soil to help rebuild soil quality. Clover is wonderful to control erosion problems in poor soils on sloping areas and great if you have animals that feed on your grass. You can purchase seed for white or red clover at many nurseries or feed and grain stores to plant in areas where you want a natural look--like in fields or along the side of the road where road salt kills everything else during the winter. Red clover is taller growing, has larger flowers--a larger growing plant overall but not as hardy as the white clover. White is more drought-tolerant, flowers more, is more aggressive and makes a better food for wildlife. If you do not like clover in your lawn, white clover is the most difficult to remove. It will take several applications of a broadleaf weed killer to control it. A little prayer to St Patrick could help!

If you are a lawn fanatic, clover is often considered a lawn weed and can be easily controlled with a broadleaf weed application about the time that the dandelions begin to flower on your lawn. If well-established, a second application will be needed 10 days later to kill the plant. But this week is for the Shamrocks and clover plants. They were sent to us by St. Patrick to protect our open areas of soil against wind and rain erosion problems. They will rebuild the quality of the soil, helping other plants to grow where they were not able to at one time. They are also a wonderful food source for animals and flowers for the bees to make honey. So this week, be sure to wear a bit of green on Tuesday and make it a three leaf clover--a Shamrock. ENJOY!