Fertilizing plants or a garden is an important part of gardening.  Depending upon the conditions, many plants can survive without fertilizer, but if they are properly fertilized they will flourish.  When it comes to fertilizing, timing is very important.  If the timing is off it could seriously affect the growth of the plants.  Getting the timing just right can be tricky because it can vary between regions of the country.  To make it a little easier we are going to outline a fertilizing schedule for several types of plants in Utah.

Flowers

These plants are not very complicated to fertilize, but there are various ways to go about it.  For annuals it is best to start in April or May depending upon your personal taste and weather conditions.  Once the soil has dried out a bit from winter it is a good time for a gardener to prepare their garden for any new plants they may add.  This is usually done in April.  As they mix up the soil they can add some slow release nitrogen fertilizer.  A good type of fertilizer to use will have the numbers 5-10-5 on the bag.  These numbers represent the nutrients phosphorous, nitrogen, and potassium.  When the soil is mixed up it is also beneficial to add a form of organic fertilizer, such as compost, to the soil.  If a gardener wants to wait until May they can add in the fertilizer as they plant their new annuals.

A fertilizing schedule for annuals can also start in June, but it is a little more work.  If by June no slow release fertilizer has been used on the flowers, a gardener can apply water-soluble fertilizer.  This type of fertilizer is used up faster than slow release, so it should be applied at regular intervals.  If you bought fertilizer from a store it is important to look at the bag to determine when the fertilizer should be applied next.  Organic fertilizers can also be used, and they are usually used once a month.  By August most of the fertilizing is done, but a gardener can add some more slow release fertilizer if they so choose.  In order to do safely apply the fertilizer six to eight weeks needs to have passed since the last application.

For perennials it is ideal to start fertilizing in April.  If the soil does not already have organic fertilizer in it, slow release fertilizer should be added when the flowers are planted.  If there are any perennials that bloom late more slow release fertilizer can be applied in July if it has been at least six weeks since the last application.

Shrubs

The fertilizing schedule for shrubs only requires fertilizing once a year.  It sounds easy, but it can be a bit difficult with regards to the timing.  Fertilizer can be applied in either spring or fall.  If a gardener chooses to fertilize their shrubs in spring it should be applied approximately a month before leaves appear.  Fall fertilizer should be applied about a month after the first frost.  Fertilizing in fall is a bit simpler than spring, because the timing for spring is a little more difficult to measure.  Spring fertilizing will be easier for a gardener that has kept a gardening journal.

Whether a gardener decides to fertilize their shrubs in spring or fall, they should use a half cup to a cup of fertilizer for every shrub. The fertilizer should have 10-10-10 on the bag, which qualifies the fertilizer as a complete fertilizer.  When applying the fertilizer it is important to spread it out across the entire area where the roots are to ensure more than one area of the shrub absorbs the nutrients.

Vegetable Gardens

These gardens may seem a little daunting because they generally contain so many different types of vegetables.  It is important to keep in mind that they are all plants, and they all need the same nutrients.  Since they require the same food an entire garden can usually be fertilized using one type of fertilizer.  Utah’s soil tends to lack phosphorous and nitrogen, so it is a good idea to use a 10-20-0 fertilizer.  It is recommended that three pounds of fertilizer be used for every 100 square feet of garden.  When the fertilizer is being applied it is important that the fertilizer is not placed too close.  It should be placed either three inches to the side of the seed row or six inches into the soil.

Grass

A lawn may not be the first thing that comes to mind when a gardener thinks of fertilizing, but it is a very important part of a home’s landscaping.  It requires care like other plants in a yard.  Fertilizing a lawn can be a little difficult to get right because there are so many different types of grass.  Utah has both warm season and cool season grasses, which can make things difficult.  The most popular warm season grass is Zoysia, and the most popular cool season grass is Kentucky Bluegrass.  The good news is the fertilizing schedule for both types of grass starts out the same.  In the late spring around the end of May or the beginning of June about ¾ to one cup of slow release fertilizer should be spread on a lawn.  The fertilizer should be applied when rain is expected to help the fertilizer sink into the ground.

After the first application, the fertilizing schedule for the warm season and cool season grasses splits temporarily.  Warm season grasses often require another application about six to eight weeks later.  Cool season grasses only need to be watered until the fall.

The next fertilizer application should occur in late summer or early fall.  The best time to apply the fertilizer is when the heat has died down but the grass has not gone dormant yet.  It is important to monitor the night temperature because the fertilizer should be applied once the temperature goes below 55 degrees.  For this application about ¾ of a cup should be used.

The last phase of the fertilizing schedule comes in late fall.  Usually in November grass has gone dormant or has stopped growing enough so it does not need to be mowed.  At this time either water soluble fertilizer or slow release fertilizer can be used.  If a gardener decides to use a water soluble fertilizer, which immediately provides all its nutrients to the grass, they should use one pound per 1000 feet of grass.  Using slow release fertilizer will require one and a half to two pounds per 1000 feet of grass.