Time to Plant Virginia Native Bulbs

Planting in this area starts in mid to late October for most bulbs. Planting after the first hard frost (late October or early November) is best for tulips. Bulbs are not shipped after early December, so plan accordingly.  There are some exceptions to fall planting – Colchicum is best planted by early fall before it blooms.

Planting Depth and Width – Use the general three times rule when planting most dormant bulbs Plant about 3 times the height of the bulb (measured from the soil surface down to the tip of the bulb).  Space bulbs at least three times their width apart.  Actual planting depth can vary from about2 times to 4 times the height of the bulb – bulbs generally are not sensitive about planting depth.  The pointy end should be facing up and the rooting side (basal plate here) should be at the bottom of the hole.  If you are uncertain about what is the top vs. the bottom, plant the bulbs on their sides.  Plant bulbs in groups for the best visual impact, with shorter bulbs going in front of taller plants (the height of plants at the time of bulb bloom, not mature height).  

Light and Moisture Requirements – Most bulbs do best year after year when planted in full sun.  Bulbs suitable for light shade or part shade, especially if they get full sun in the spring until trees leaf out, are noted in the comments column.  Most bulbs that go dormant in the summer prefer moist soil in the spring and/ or fall and prefer drier sites in the summer.  Most summer blooming bulbs prefer moist soils.  Most bulbs need good drainage – Camassia is a notable exception. Water bulbs after plantings to initiate root growth if it is not raining at least ½ inch per week.

Fertilizer is Seldom Needed – We rarely fertilize bulbs at Green Spring because our extensive 2 use of leaf mulch makes our soil fertile. According to the International Flower Bulb Centre in the Netherlands, bulbs prefer a fertilizer with low levels of nitrogen in the fall (e.g., 5-10-12 or 4-10-6) if fertilization is needed. Organic fertilizers or slow release fertilizers are best for the environment. If spring fertilization is needed, the Bulb Centre recommends fertilizing no later than 6 weeks before flowering (fertilizing any closer to bloom can encourage disease) or right after bloom ends. A fast-release inorganic nitrogen fertilizer can be used in the spring because actively growing plants take up nitrogen rapidly. Lightly scatter fertilizer on top of the soil – do not mix it into the planting hole because bulb injury can occur.  Alternatively, top dressing bulbs with compost or mulching with shredded leaves are excellent ways for gardeners to increase soil fertility.

Let Foliage Die Naturally – Cut back only a little foliage here and there if bulbs are flopping on other plants because you do not want to reduce the vigor of your bulbs.  Bulbs continue to produce food after they are done blooming, until the foliage goes dormant.  Miniature bulbs have less dying foliage to look at, so use them if you like bulbs but not the look of spent foliage in May, June, and/ or early July.  Planting perennials and tender plants around bulbs can help to hide their foliage as they go dormant.  

Divide Bulbs If They Get Crowded After Several Years – This is an issue with some bulbs, such as many daffodils.  They can be dug up from about the time they go dormant (late June/ early July) through fall.  It is better to do this task earlier rather than later because they are not actively growing in the summer and you will cause less damage.  Separate the bulbs from each other then replant at a wider spacing and in new areas.  The following is a list of hardy bulbs that perform well in the Washinton DC area.


Planting Camassia cusickii "Camas"

 

 
One of the easiest to grow native bulbs available Thrives in moist winter and spring soils A favorite elk and moose graze in early spring Perfect for massing in a rain garden Unparalleld blue flower color

This is a native bulb that thrives in moist soils. Broad, grass-like leaves form a clump that gives rise to long, bud carrying stems that open to reveal brilliant blue, star shaped flowers in mid-spring.  This bulb thrives in moist areas but will tolerate dry soils and is easy to grow.

 

Height: 12-36 Inches  Spread: 6-9 Inches

 

Choosing your site:

Camas prefers moist soil conditions such as wet meadows and prairies, depressions, moist hillsides and streamside areas.  In the wild, these areas tend to be high in silt and clay and will dry out in the summer.  If you do not have such an area in your garden, irrigation may be necessary. 

Plant your camas in an area that receives full sun to partial shade.  It is also recommended to choose a site with little competition from dense stands of live grass.

When to plant:

Optimum planting time is in the fall or early winter.  Camas seed will require 42-100 days of cold temperatures (34-40�F) under moist stratification for optimum germination.  The camas seed is highly sensitive to warm temperatures, if exposed during development it can be lethal. Soil temperatures should be cool (below 60�F) and the soil should be moist. 

How to plant:

Scatter your seeds directly over the soil surface on your desired site and cover with 1-2 inches of organic mulch (sawdust works well) � this will help protect the seed from exposure to soil drying and cracking and extreme temperatures.  A minimum of 20 seeds per square foot is recommended for good seedling counts in the spring.

If planting bulbs, soil depth should be between 4-6 inches.  This depth can vary depending on the maturity of the bulb.  If for example, you decide to propagate some of your own bulbs after a year or two, you should plan on sowing them 0.5-1 inches in the ground.

Maturation:

Seedlings may take 3 years before a bloom is generated, if planting bulbs, look for the flowers to appear the following spring.  Camas flowers generally bloom from April to June.

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