I'm a beginner. Can you plant a perennial in a pot and will it come up each year?
The problem with planting in containers is that the roots of your perennials can freeze solid during the winter months unless you protect them by burying the pot in the ground or wrapping bubble wrap or a garden insulation blanket around the outside of the pot to keep the roots from freezing. If you can't do this, you might want to just plant annuals with the expectation that you'll have to replant every spring.   

Can I use outdoor soil for indoor plants?
Place indoor plants in potting soil, not garden soil, which can be heavy and cause poor drainage in a small container. Check the package before buying soil to ensure that the product can be used in containers. If it says it’s safe for houseplants, go ahead and use it indoors. Potting soils from Miracle-Gro, available in-store, are great for container plants.  

I planted vegetable and herb seeds in an indoor seed starter and now mold is growing on some of the soil. What can I do?
Remove the top of your seed-starting tray for a few minutes each day to allow excess moisture and humidity to escape. If the inside stays too humid, your seedlings can develop a fungal disease called “damping off.” As soon as you lift the top to allow fresh air to enter, the mold should begin to die. As a rule, the top only needs to be in place until the seeds sprout; after they sprout, you can remove the top for good.  

Do I have to repot houseplants after I take them home or can I leave them in the nursery container?
Houseplants should be transplanted when they’re pot bound. How long that will take depends on the plant and the size of its pot. Wait until the roots begin to escape through the drainage holes, then place in a pot 1 size larger. You’ll find planters at your local The Home Depot in a variety of colors, styles and sizes.  

My kalanchoe plant was flowering when I bought it but now, 2 years later, the flowers won’t come back. I recently transplanted it to a bigger pot but it hasn’t helped. I keep it by a window with lots of light but no direct sun. What can I do?
Set it in a very sunny window and water it moderately. To force it to bloom indoors during winter, you need to manipulate the amount of light it receives. In the fall, place it where it will receive total darkness for about 15 hours every night. (Cover it with a box, put it in a closet or leave it in a room without artificial light so it experiences the decreasing daylight hours.) Do this every night for 6–8 weeks. This will encourage it to set buds and bloom. When growth slows after blooming, cut back on water. When growth resumes in spring, increase watering again and fertilize lightly with a water-soluble fertilizer from Miracle-Gro or Osmocote, available in-store. In summer, place your kalanchoe plant outdoors as soon as temperatures rise above the high 50s.  

I’ve heard that sunflowers can poison the soil and that vegetables shouldn’t be planted near them. Is that true?
No. Sunflowers don’t release a chemical that interferes with the growth of other plants. However, their dropped seeds can cause a nitrogen deficiency in the soil and temporarily inhibit growth. This is easily fixed with a dose of nitrogen fertilizer from Vigoro, available in-store.  

I’m starting to plan my spring garden, but I recently got a dog. What plants should I avoid to protect him?
Since dogs love to nibble on plants, avoid ones that are known to be toxic to pets. Common ones include flamingo lily (Anthurium), castor bean, foxglove, jasmine, oleander and tomato plants. Instead, choose animal-friendly plants such as bamboo, catnip, lavender and marigold (but not marsh marigold).  

I was given a compost tumbler but I know very little about composting. How can I get started?
It’s pretty simple—eventually, everything will turn into compost. To speed the process you need 4 ingredients: carbon (leaves and woody pruning from the landscape), nitrogen (grass clippings, kitchen fruit and vegetable scraps), water and oxygen. Start by mixing the carbon and nitrogen products in equal amounts. After placing your materials in the tumbler, add a shovelful of soil, which contains beneficial micro-organisms. Turn the barrel every other day to mix the materials and add fresh material as you collect it so it will develop into compost as early as 4–6 weeks.  

I've had groundcover (jupiter)in a bed for years and I've decided to remove it to plant and flower garden. problem is I've been cutting down with the lawnmower then tilling over the past couple of years only for it to return. what can I use to completely remove the roots and all without killing the soil so I can plant a flower garden.
Sounds like it's time for an herbicide application. You can use Round Up to kill the vegetation. When the jupiter is dead, rake it out of the bed, roots and all. If you miss some of the underground roots with the herbicide, they may sprout and you'll need to spot treat them. I wouldn't plant anything until you're sure the jupiter is dead. Round Up is a vegetation killer that will be transported down to the roots of the weedy plant but it won't move in the soil. As long as you rake out the dead plants and roots, the soil won't retain any of the chemical. Read the label - I think there's a 3 week waiting period after using Round Up and before planting in the bed. Good luck with your eradication project!  

My backyard only get the afternoon sun (Light Shade) Though things will grow, they grow slowly and will not produce fruit or flowers or flower. WHAT KIND OF FLOWING PLANTS ARE BEST FOR THIS AREA
Here are some fairly tolerant plants to try in your part sun/part shade garden: shorter varieties of daylily (hemerocallis), perennial geranium, purple coneflower, heuchera (coral bells), variegated liriope, bleeding heart, various types of sedum and the annual, fibrous rooted bedding begonias.