By Heather Kirk-Ballard
LSU AgCenter Horticulturist
Spring is here and the plants are booming. Plants perform best when they are getting the optimum amount of sunlight, appropriate amounts of water and plenty of essential nutrients for good growth and production of flowers and fruit. Optimize plant growth by knowing how and when to fertilize.
Fertilizers provide the nutrients needed by plants to grow, form flowers and healthy foliage, produce more fruit, establish a strong root system and fight diseases and insect pressures. Plants benefit from fertilizer applications most when they are in their peak growth, and spring is one of those times!
The best time to fertilize is when many plants come out of dormancy in the springtime. In spring, deciduous plants leaf out, flowering plant buds begin to burst, stems and branches elongate and new roots are formed. Nutrients will aid in all of this growth, so the rule of thumb is to make an annual application of fertilizer in the early spring.
There are several ways to fertilize plants, including slow-release granular fertilizers, liquid feed applied to soil as a drench, foliar sprays and fertilizer stakes. In addition, using natural fertilizers such as compost can add nutrients to your soil.
Compost is decayed organic material from other plant materials and animal waste from livestock that has a diet mostly made up from plants. Those include chickens, cows and horses. Composts can be found already bagged at many retail garden centers or available in bulk delivery form from local sources.
Compost also can be made from waste such as grass clippings and fallen leaves in your yard, in addition to kitchen scraps such as coffee grounds, eggshells and fruit and vegetable peelings. Worm castings and mushroom composts are two additional composts that add nutrients to your soil.
Plants can have individual needs when it comes to fertilizers. Acid-loving plants such as azaleas, blueberries, camellias, hydrangeas and rhododendrons prefer more of an acidic soil pH to take up optimal nutrients. Flowering plants need more phosphorus to help stimulate stronger bud, fruit and flower development.
Vegetable plants benefit and require more frequent fertilizer applications throughout the season because they are producing and that makes them heavy feeders. Slow-release fertilizers can be incorporated at planting time for extended nutrient release. Side dress with calcium nitrate at the first and third bloom set. Additionally, some growers utilize liquid fertilizers every other week.
Nitrogen is very important for all plants but especially important for lawns and turfgrasses. Woody plants such as shrubs and trees can benefit from an application of three pounds of nitrogen per thousand square feet and perennials benefit from one pound of nitrogen per 1000 square feet in the spring.
Indoor potted plants may be fertilized with a liquid plant food every month for most varieties. Do this once each season in spring, summer and fall, but skip winter for plants that go into dormancy. No matter the plants you are trying to feed, scheduling the correct timing is important.
Applying fertilizer in the wrong season can cause increased tender new growth that can be damaged, especially if applied in cold weather in late fall or in winter. So it is best to stop fertilizing during dormant seasons. Additionally, in zones that can be in danger of a late freeze, it’s best to wait until mid-spring. Everyone could benefit from putting fertilizer application schedules in their calendars.
Here are some general rules to follow when fertilizing:
- Avoid fertilizing new plants until they are fully established, because it can cause an increase in tender new growth that can make the plant weak and leggy.
- Always follow the manufacturers recommended rates and application methods.
- Fertilize outdoor plants in the coolest part of the day, such as early morning or late evening, especially in hot summer weather.
- Always water in fertilizers well to distribute nutrients throughout the soil profile and to prevent burning.
- Lastly, avoid excessive fertilizing and perform soil tests annually to see what nutrients your plants need.
With fertilizer prices doubling as they have, waste not!
A goodslow-release fertilizer and use of liquid fertilizer when needed will helpproduce the most flowers and fruit. Photo by Heather Kirk-Ballard LSU AgCenter
Mushroomcompost can add nutrients to soils and potting media. Photo by HeatherKirk-Ballard, LSU AgCenter
Slow-release granularfertilizers can be applied in spring for continual feeding. Photo by HeatherKirk-Ballard, LSU AgCenter
FAQs
Plants benefit from fertilizer applications most when they are in their peak growth, and spring is one of those times! The best time to fertilize is when many plants come out of dormancy in the springtime.
What happens if you don't water after fertilizing? ›
Why Water After Fertilizing? Watering after fertilizing washes the fertilizer off of the grass blades and into the soil, where it can get to work nourishing your lawn. It's also important because if fertilizer sits too long without being watered in, it can burn the grass.
How many minutes should I water my lawn after fertilizing? ›
The goal is to soak your lawn until the soil is moist to a few inches deep. The exact amount of time that this may take will depend upon your lawn and its sprinkler system. On average, it could take around 45 minutes to an hour. Of course, Mother Nature will hopefully also be doing some of the watering work.
When should I stop fertilizing? ›
Stop fertilizing in late fall as soil temperature drops. Avoid fertilizing on very hot days when plants are working hard to stay hydrated. Apply fertilizer a day after thoroughly watering plants to prevent leaf burn.
Should you fertilize your lawn before or after it rains? ›
It's best to wait until after it rains when the grass blades are dry and there will be sunlight in the coming days. These conditions provide an ideal environment to ensure maximum fertilizer effectiveness!
What is a good fertilizer schedule? ›
Mid to end of APRIL – spring fertilizer – 32-0-6 slow release (fast acting) Early to mid JUNE (6 weeks later) – early summer fertilizer – 25-0-5 – 50% slow release. Mid to late JULY (6 weeks later) – late summer fertilizer – 25-0-5 – 50% slow release.
Is morning dew enough to water in fertilizer? ›
Morning dew can also help with fertilizer, which creates enough moisture for the grass to take the fertilizer. Dew reduces water stress on your lawn and plants so when water is on grass, it reduces transpiration.
How long does it take for granular fertilizer to dissolve? ›
Most granular fertilizers dissolve within 24 to 48 hours, though the formula and brand may impact the overall dissolve time. Read through the packaging to get a better idea of how you should apply the fertilizer and how long you should wait to mow to ensure it dissolves properly.
Should you water after fertilizing with Scotts? ›
It depends on the fertilizer. Some lawn foods perform better when you water them in right after applying, while others—such as some weed-and-feed products—need to be watered a day or two after fertilizing. It all comes down to this: Check the product directions on the bag—they'll tell you when to water.
Does fertilizer need to be watered in immediately? ›
You should water granular fertilizer immediately after it is applied to your plants. Granular fertilizer needs the help of water for it to activate, so it will have no effect on your garden if you forget to water after adding it. For liquid fertilizer, you should wait longer before watering your plants.
Ideally, you shouldn't fertilize the lawn until the ground is consistently at least 55 degrees Fahrenheit. Early morning is a good choice so you can take advantage of the morning dew, which will help the fertilizer soak into the soil.
Can you over fertilize your lawn? ›
Applying too much fertilizer to your lawn will cause the nitrogen and salt levels in the soil to increase rapidly, which can damage or even kill the grass. When this happens, it is known as “fertilizer burn” and looks like yellow and brown strips or patches of dead grass.
Do you cut grass before fertilizing? ›
Before applying fertilizer to the lawn, it's important to mow it first to clear away any thatch. This allows the fertilizer to make better contact with the soil. When the spring fertilizer makes better contact with the soil, it will be absorbed more easily by the roots of your grass.
Is it okay to put fertilizer on dry grass? ›
While it's generally a good practice to fertilize a dry lawn, applying treatment during a drought is not advisable. The heat can place significant stress on your lawn, and fertilizer might not be the ideal solution.
Is it okay to spread fertilizer on wet grass? ›
You can usually apply most non-liquid granular fertilizers to wet grass, but not saturated ground. If there are ponds or heavy rain, it's best to wait until the ground processes the water before applying any type of fertilizer. If there's light rain, it's okay to spread dry granular fertilizer.
How long can fertilizer go without water? ›
We recommend waiting 24 hours after fertilizing to water your lawn, which will give the fertilizer time to settle. After the 24 hours are up, it's important to give it a good soak—not just a quick spritz with your hose—to activate the fertilizer and help the critical nutrients absorb into the soil.
What happens if you fertilize and it doesn't rain? ›
As a side note, never apply fertilizer when extended drought conditions are expected. It won't do your plants any good; you'll waste money on fertilizer because it will eventually become inactive, and whatever is left will simply wash away in the next big rain.
How long is fertilizer good for without rain? ›
For fertilizers we tell you to get them in within 48hrs. This is because the longer it sits there without being watered in, the longer it's going to take you to see results. There is also a greater chance of a gully-washer rainstorm coming through that could push some of your fert out into the street.
Can you fertilize plants without watering? ›
Never apply fertilizer to dry soil. It's important that the soil is evenly moist before adding the fertilizing liquid. Water until water drips from the pot into the saucer.
