Navigating the fertilizer aisle

Posted by tonka_admin on Apr 28th 2016

Like children and pets, plants need food. It can be more difficult to know the what, how, and when of feeding plants, however, and this can make navigating the fertilizer aisle a little daunting - but it doesn’t need to be. Here are some basics to make your next trip to fertilizer-ville more pleasant.

What do those numbers mean?

Each package of fertilizer will have three numbers, such as 10-10-10. These numbers indicate how much N-P-K, or nitrogen, phosphorus, and potassium (respectively), is in the product. Different plants need different amounts of food. Each element does a little something different for a plant. Nitrogen encourages vigorous, green growth. Phosphorus promotes blooms and strong root growth. Potassium also promotes root development and strengthens the plant against stressors. A fertilizer with 20-0-0 on the label will promote lush green growth but won’t do much for flower production. Such a product would make for a good lawn fertilizer but won’t do much to impress your geraniums. Look for a fertilizer that has the plants you’re feeding, or very similar plants, on the label. When feeding your plants, remember that more is not better! Too much fertilizer can burn the roots and cause the plant to shrivel and die. Follow the label, or even use a little less than recommended to be safe.

Who needs fertilizer?

Plant foods at Tonkadale GreenhousePerennials don’t need to be fertilized very often. Once in early spring and once in mid-summer is fine. Unless you’re fertilizing something with specific requirements – such as blueberries that want acidic fertilizer – just use a basic garden food with a balanced N-P-K ratio. Good choices include Espoma Plant Tone (5-3-3) or Espoma Garden Food (10-10-10). Both come in granular form and can be scritched into the soil for slow release throughout the season. Annuals need food more often. Fertilize every week or two with a basic fertilizer. Miracle-Gro All Purpose Plant Food is an easy-to-use option. Just mix with water and apply. Plants will absorb the nutrients through their leaves and roots. Osmocote is another great option. Just sprinkle on the soil and water. It’s especially great for hanging baskets and window boxes that are easily accessed with a water wand but not a watering can. For bigger, more prolific flowers, try Miracle-Gro Bloom Booster Flower Food (15-30-15). That bigger middle number means there’s more phosphorus to promote better color and more blooms. One of the easiest ways to choose a fertilizer is to look for one that specifically lists the plant you are growing. Tomatoes like their food a certain way, and giving them what they want will make for happier, healthier plants that are more productive and disease resistant. Espoma Tomato Tone (3-4-6) is designed to feed tomato plants and promote flower and fruit production without causing rapid green growth. Neptune’s Harvest Fish and Seaweed Fertilizer is also a good choice. Tomatoes love fish fertilizer - but beware! Dogs love it, too, so you will want to keep them out of the garden for a little while after applying. Other specific fertilizers include Espoma Rose-tone, Espoma Bulb-food, and Espoma Soil Acidifier or Miracle-Gro Miracid, which both fertilize as well as contain elements necessary for turning hydrangeas blue and keeping blueberries happy.

Wait, what’s up with compost?

Compost at Tonkadale GreenhouseAnother important consideration for growing healthy plants is the condition of the soil and the potential need for amendments. Compost is made from animal waste or organic matter and is a great amendment. It should be completely broken down and have the look, feel, and smell of soil. When applied to the garden, it helps loosen clay soils and provide drainage and when added to sandy soil it provides water holding capacity. Compost will contain some amount of naturally occurring fertilizer, as well. If you make your own compost be sure it’s completely broken down so it doesn’t burn plant roots. If you purchase compost, buy from a trusted source. Good options include Coop Poop (from chickens) and worm castings (yup, worm waste). One way to know if your lawn or garden is deficient in an important nutrient is to have a soil test completed. The University of Minnesota does this for a small fee, and they will help you interpret the results as well. There are many other types of fertilizers that are formulated for specific plants, taking the hard work out of measuring and making the whole process easier. We’ll help walk you through it - we’re committed to your gardening success and always happy to help you find the perfect food to grow perfect plants. Whatever you grow, remember to feed it – you and the plants will be glad you did!