Frequently Asked Questions

Here you will find a list of Frequently Asked Questions. If your question is not answered here, please feel free to contact us directly.

Planting depth:
Bulbs are usually planted with 3 to 4 inches of soil above the bulb. Be sure to pack the soil down prior to measuring planting depth. Planting too deep can hurt the bulb’s ability to produce a flower.

Planting density:
Tulips and iris can be planted at 9 to 12 bulbs per square foot. Lilies can be planted at 6 to 8 bulbs per square foot. Larger bulbs and varieties that produce above average foliage may need to be planted at a lower density. Certain varieties will gain in length when planted close together. The closer the plants are, the greater the risk of botrytis.

Preferred soil type:
Bulbs like well drained soils. You do not need Dutch style sandy soils to grow good bulbs, but you will need good drainage. If you have heavier soils, planting the bulbs in raised beds or hills will help improve drainage.

When to plant bulbs:
Tulips and Iris can only be planted in the fall. Generally speaking they can be planted once the soil temperatures have cooled down. In Western Washington, the second half of September is the earliest one can plant, with October being the usual time. Do not try to plant if the soil is saturated with water. Try to plant prior to the chance of night frost.

Lilies can be planted (or forced) throughout the year. However they do need conditions that allow them to continue growing. Colder temperatures, shortening days, and lower light levels, are all signs to the bulbs that its window of opportunity is closing. Plant a lily too late and it will produce a nice stem, but the flowers will likely abort.

Winter cooling requirements:

Most bulbs have a cooling requirement (this varies for different bulbs). This cooling requirement protects the bulb from starting to grow in the winter. Once they have met this requirement, a bulb is ready to grow normally when spring arrives.

Tulips and Iris are planted in the fall and will receive this cooling naturally. This is why tulips do not do as well in areas with warm winters. Tulips that are forced for cut flowers in the winter and early spring are given cooling (pre-cooled) prior to being brought into a greenhouse. Lilies receive this cooling naturally if planted in the fall or while being stored in coolers through the winter. Lilies can be stored around 32 degrees F. and will usually have their cooling requirements met in January.

Blooming/Forcing time:

The longer a lily is stored, the quicker it can be forced. Thus the difference in forcing time between lily bulbs planted in January versus March is a lot, but the difference in the actual blooming time will be very little. Though the lily bulb planted in January has 60 more days to grow, the climate conditions in January and February are cold enough to slow down the lilies growth. While the lily bulb planted in March has had 60 extra days of cooling in storage and will be planted in a warmer season. Thus the March planted lily, with its extra cooling and the warmer season, will offset the January planted Lily’s extra growing time. However the difference in blooming time between lily bulbs planted in March versus June will be much greater. Lily bulbs planted in June and July are often forced 25-33% faster than if planted earlier in the year.

Tulips and Iris will have different blooming times based on the variety. Climate and weather conditions will always have an affect on when a bulb will flower. Thus the “normal” blooming time for Minnesota will not be the same as for Washington, nor is 2010 likely to be the same as 2009.

Where to plant:
Do not plant bulbs in the shade or in soils that have standing water on them at any point. Fields that allow air to move through the crop are preferred. This allows the foliage to dry during the day which in turn reduces the chance of botrytis.

What does the bulb size number mean:
Bulb sizes are generally given in centimeters circumference. Thus a 14/16 would have about twice volume when compared to a 10/12.

How does bulb size affect the plant:
A larger bulb size will usually increase the length and girth of the stem. Lilies will gain 1 to 2 inches of height, on average, for each larger size. For bulbs that produce multiple flowers per stem, a larger bulbs size means more flowers per stem. For bulbs that only produce one flower one will see an increase in the flower size.

Which herbicides can be sprayed on or around bulbs:
To control weeds around bulbs one can spray various herbicides. When spraying an herbicide make sure that it does not drift onto your crops and that it is not an herbicide that can leach into the bulbs root zone and be taken up by them. Most weeds can be controlled with an application of Roundup (which is also available under different trade names). For clovers and vetch it is best to use a 2-4D product (which will control only broadleaf weeds and not grasses).

Always read and follow all chemical and pesticide labels. Check with your local farm and garden store or pesticide supplier to get more exact information on what is available and legal to use at your location.

Avoiding and containing botrytis:

Botrytis spreads easiest when it is cool and damp. Foliage that stays wet for over 24 hours in these conditions has a greater chance of being infected by botrytis. This is why it is important not to plant too densely if in a location that can expect conditions that botrytis prefers. Placing your rows so that they are parallel to the normal direction of the wind at your location will help keep the foliage drier. For our location (west of the Cascades), the summers are very dry, thus the density can be increased (with the added benefit of gaining a little more length).

If you spot a plant with botrytis, remove it from your crop and move it far away. Make sure that the amount of old foliage from the previous year is kept to a minimum helps as well. There are various contact fungicides that are labeled for bulbs which can be sprayed to contain a botrytis outbreak. Contact fungicides often have noticeable residual after applying them which will wear off over time. There are also a lot of systemic fungicides on the market that can be sprayed to help prevent botrytis.

Again, always read and follow all chemical and pesticide labels. Check with your local farm and garden store or pesticide supplier to get more exact information on what is available and legal to use at your location.

Which lilies are up facing:
Generally speaking all lilies used in the cut flower industry (forcing lilies) are upward facing. In the heat of the summer some varieties will face out more. Many of our Orienpets are out or down facing. Some well known varieties that are also down facing are Conca D’Or and Casa Blanca.

What is the difference between an Asiatic and a LA:
LAs are crosses between an Asiatic and Longiflorum. For the grower what it means is that LAs tend to have fewer but larger flowers on average than do Asiatics. LAs also tend to be above average growers. Asiatics tend not to make as much bulb size as do the LAs but usually have a higher bud count and are a little less fragile.

What is the difference between an Oriental and an Orienpet (OT):
Orienpets are crosses between Orientals and Trumpets. Orienpets tend to have a lower bud count and be less up facing. Orienpets are also usually hardier and do not have as much of a cooling requirement. Orienpets often need a larger size to produce a similar bud count. The addition of the Trumpet genes in the Orienpets allows them a greater variety in colors and shapes than do Orientals.

Can bulbs be used for cut flowers the following year:
Tulips and Iris are considered a one year crop. Lilies can, in some instances, be cut for more than one year. To try this, it is suggested to purchase a large size and, when cutting, to leave at least 12 inches of stem/foliage standing. This will allow the bulb to recoup some of the reserves that it has spent growing the stem and flower. Even in a best case scenario there is no guaranty of success. Van der Salm Bulb Farm does not have experience with such techniques; this is just what we have heard from various sources.

When to order:
Please order when you would like. However, know that certain varieties are hard for us to purchase and thus in limited supply. Other times we will purchase or keep in inventory what we think we can sell. Early in the season we can often purchase more of a certain variety, if it shows to be very popular. Later in the season we will only have the inventory we have on hand without the ability to obtain any additional product. If there are certain varieties that you are sure you would like to purchase, please feel free to order as soon as we have our pricelist out. Orders can always be added to at a later date.

Canceling items or orders:
If you have to cancel an item, we would appreciate you doing so as soon as you can. The earlier we have an item back on our availability, the more likely we are to be able to re-sell that item. If you cancel an order or item past our cut off dates, you will be charged a restocking fee of $25 per box.

When can I have my order shipped:
Once we have the item in inventory, we can ship as soon as you would like. Sometimes we will have some of the items on an order in inventory and still waiting for the balance. In such cases we let the customer decide if they would like to split the shipment or wait for the rest of the order and ship it complete at one time. We have coolers and heat rooms on site to maintain product quality during storage. Van der Salm Bulb Farm will not be held responsible for product being shipped too late, but we will do our best to inform the customer as to the best planting period.

What are my shipping options:
For smaller orders, Van der Salm Bulb Farm ships via UPS. Mondays are our designated UPS shipping days. We charge a flat shipping and handling fee which is based on the customer’s location. For orders over 5 boxes, UPS usually has a small discount. Customers can also choose to pick up the product at our location. To do this, advanced notification must be given. This way we will have the product and paperwork ready upon your arrival.

For larger orders we can ship via LTL. Larger customers also can arrange their own transport, with proper notification to Van der Salm Bulb Farm and with our agreement. Full or partial truck loads are also not a problem. We have a loading dock on site with plenty of room for semi trailers.