The temperature in your grow room is very important for the photosynthesis of your marijuana plants. For example, low temperatures reduces evaporation through the leaves. The result is that the suction force, which takes up nutrients via the roots, becomes smaller.
Yes, you can make contributions to your IRA, subject to the IRS annual contribution limits ($5,500 for the 2015 tax year, $6,500 if you're age 50 or older). But you must keep Roth IRA and traditional IRA money separate.
You can definitely contribute to a Roth IRA too. However, according to the IRS for the 2011 tax year : Contributions to a traditional IRA reduce your limit for contributions to a Roth IRA. There is a chart in Publication 509 from the IRS that lets you figure how the Roth IRA contribution will affect your traditional IRA contribution limit.