Gardeners and baseball fans may love May. But investors often dread its arrival.

That’s because May through October is typically the weakest six months of the year for stocks.

According to the Stock Traders Almanac, since 1950, the Dow Jones Industrial Average has gained an average of 0.5% in the May 1 - October 31 period. That’s a lot less than the average of 7.9% the index has gained in the November 1 - April 30th period. The Almanac takes it a step further, with a six month investment switching strategy:

Let’s say you invested a hypothetical $10,000 in the Dow during the 'best' period and switched to treasury bonds during the 'worst' period in every year since 1950.

According to the Almanac, you would have earned a compounded $578,413 through 2006. However, if you took the same $10,000 and invested it the other way around, you’d have just $341 compounded.

I like factoids of this nature, but, personally, I can’t see investing this way. I am the type of person who invests a little into mutual funds each month, regardless of the calendar or market conditions.

What about you, do you pay attention to seasonal factors? If you have a lump sum -- like a bonus or tax refund -- do you try to figure out the perfect time to invest it? How much credence do you give to seasonal factors?