When to Plant Sunflowers in Washington State: Don’t Miss the Sunshine

Although sunflowers are typically associated with warmer climates, they can actually be grown in a variety of locations. In the United States, sunflowers are commonly grown in the state of Washington. If you’re thinking about planting sunflowers in Washington state, there are a few things to keep in mind.

It’s important to know that sunflowers need full sunlight to thrive. Make sure to choose a spot in your garden that gets plenty of direct sunlight throughout the day.

You’ll need to decide when to plant your sunflowers. The best time to plant sunflowers in Washington state is usually sometime between mid-March and mid-April. This will give your plants enough time to grow and bloom before the hot summer months arrive.

Make sure you have enough space for your sunflower plants to spread out. Sunflowers can get quite large, so giving them plenty of room to grow is important.

If you follow these tips, you’ll be well on your way to growing beautiful sunflowers in Washington state!

When to Plant Sunflowers in Washington State

What is the Best Time to Plant Sunflowers in Washington State?

The best time to plant sunflowers in Washington State is in the spring, after the last frost has passed. 

Sunflowers need full sun to thrive, so make sure to plant them in a spot that gets at least six hours of sunlight per day. 

They also prefer well-drained soil, so be sure to amend your soil with compost or sand if it is heavy and clay-like. 

To ensure strong stems and prevent disease, water your sunflowers at the base of the plant rather than overhead.

How to Prepare the Soil for Growing Sunflowers

The best time to plant sunflowers in Washington State is in the springtime, after the last frost has passed. 

To prepare the soil for planting, Till the top 8-10 inches of soil to loosen it up and then mix in 2-3 inches of organic matter such as compost or aged manure. 

Then level off the area and create furrows that are 6-8 inches apart. Sow sunflower seeds in the furrows, spacing them about 2-3 inches apart. Lightly cover the seeds with soil and water them well.

Fertilizing and Watering Tips

When it comes to sunflowers, fertilizing and watering are key to success. Here are some tips to keep in mind:

  • Fertilize your sunflowers regularly, using a balanced fertilizer. Apply fertilizer according to package directions.
  • Water sunflowers deeply and evenly, being careful not to over or under water. Water in the morning so that the leaves have time to dry before nightfall.
  • Monitor your sunflowers for signs of stress, such as wilting leaves. If you see any signs of stress, take action immediately to correct the problem.

Pests and Diseases Commonly Found in Washington State

Pests and diseases are common in Washington State. Some of the most common include:

  • Aphids: These small, winged insects feed on plant sap, causing leaves to yellow and wilt. They can also transmit viruses from one plant to another.
  • Cabbage loopers: The larvae of these moths feed on the leaves of cabbage and other cole crops, causing holes and damage. They can be controlled with Bacillus thuringiensis (BT), a naturally occurring bacteria that kills caterpillars.
  • Japanese beetles: These shiny, black-and-white beetles are destructive pests of many fruits, vegetables, and ornamentals. They skeletonize leaves by eating the tissue between the veins, and can cause extensive damage in a short period of time. Hand picking and destroying adults is the best way to control them.
  • Spider mites: These tiny spider-like creatures suck plant juices, causing leaves to turn yellow or brown and eventually drop off. They are especially damaging to evergreens such as Douglas fir and western hemlock. Spraying plants with water or horticultural oil will help control them.

How to Harvest and Store Your Sunflower Seeds

The best time to plant sunflowers in Washington State is in the spring, after the last frost has passed. 

You should wait to harvest your sunflower seeds until the flowers have died back and the seed heads are dry. To store your sunflower seeds, place them in a cool, dry place.


Planting sunflowers in Washington State is an easy and rewarding endeavor. Knowing when to plant your sunflowers and how best to care for them will ensure that you get the most out of this beautiful flower. 

The optimal time for planting sunflowers in Washington State is late summer, but as long as you take into account the necessary soil preparation, watering, and fertilizing requirements, you can enjoy a wonderful display of colorful blooms throughout the growing season.

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