Are Washington Tree
Seeds the Same Size?
Douglas-fir
Ponderosa Pine
Western White Pine
Pacific Silver Fir
Noble Fir
Grand Fir
Western Larch
Sitka Spruce
Western Hemlock
Western Redcedar
Red Alder
Bigleaf Maple
Garry Oak
By
Kacey Marshall
2nd Grade, Mrs. Leto’s Class
Community Christian Academy
Lacey, Washington
Spring 2002
Are Washington Tree Seeds All the Same Size?
By
Kacey Marshall
My science project is about how big seeds are
from different kinds of trees in Washington and a
little about how they grow. There are many kinds
of trees in Washington and they all have seeds.
Their seeds are very different. A seed is a new
tree. Some tree seeds are big and some are
small.
I went to look at tree seeds at the Washington
State Department of Natural Resources Tree
Seed Plant in Olympia, Washington. Mr.
DeGraan and Ms. Pickens showed me seeds
from 11 different trees that grow in Washington.
At the nursery they collect tree seeds by hiring
people to climb trees and pick the cones. Then
they get the seeds out of the cones by heating
them so the cones think it is summer and open
up and the seeds fall out. Then they clean the
seeds, take off their wings, dry them and then
store them in big barrels in a freezer at 0oF. If
they did not dry the seed, it would explode when
they froze because water in the seed gets bigger
when it freezes. The seeds will still grow after 5
to 40 years in the freezer depending on which
kind of tree it is from.
After big trees are cut down in the forest to make
houses, paper and other things, foresters plant
new trees. When they need new trees, the
nursery gets seeds from out of the freezer and
waters them and then plants them in
greenhouses or in the ground. After 2 or 3 years
they take the trees out of the nursery and plant
them in the forest.
I also visited Dr. Harrington, a scientist at the
Pacific Northwest Research Station, in Olympia,
Washington. She gave me 2 more kinds of
seeds. I asked her why seeds are different. She
said that seeds are like baby trees and have
different plans of how to grow. Some seeds are
small and light and are blown far from their
parents to find good places to grow with lots of
light, soil and water. Other seeds are heavy and
fall down right by their parents. They are big
because they have extra food (she said it was
like having a big lunch box) to help them grow
under other trees where there is not as much
light or water.
A Douglas-fir Tree Seed
Seedcoat
Endospern
Cotyledons
Hypocotyl
Radicle
protects the seed
food supply
first new leaves
stem
roots
Here are the tree seeds I collected and how big
they can get in Washington:
Name of Tree
Western White Pine
Ponderosa Pine
Western Larch
Sitka Spruce
Douglas-fir
Pacific Silver Fir
Grand Fir
Noble Fir
Western Redcedar
Western Hemlock
Red Alder
Garry (Oregon
White) Oak
Bigleaf Maple
Weight of
100
seeds
(grams)
1.7
3.8
0.3
0.2
1.2
4.1
2.5
3.4
0.1
0.2
0.1
Biggest tree in Washington
How big
How tall?
around?
(meters)
(meters)
5
59
7
55
6
58
13
75
14
63
7
66
6
77
7
73
19
49
8
62
5
22
5.3
6
28
4.2
10
28
Defintion
Variation is how different things are.
To show how tree seeds are different sizes, I
made a graph of the weight of clean seeds.
From the graph, the biggest tree seed I found is
Garry Oak and the smallest is Red Alder. 1 oak
seed is about 5 grams and 100 red alder seeds
are about 0.07 grams. A chocolate kiss or 3
nickels are about 5 grams. The biggest tree
does not have the biggest seed.
Red Alder
Western Redcedar
Western Hemlock
Sitka Spruce
Western Larch
Douglas-fir
Western White Pine
Grand Fir
Noble Fir
Ponerosa Pine
Pacific Silver Fir
Bigleaf Maple
Garry Oak
30 maple seeds
1 oak seeds
0
1
2
3
4
5
6
Weight of 100 Clean Seeds (grams)
Weight in
grams
The seeds from the oak tree are called acorns.
The acorns I collected came from trees in
Oregon and Washington and are different in
size. I weighed the 6 acorns I collected and the
largest weighed 6.5 grams and the smallest
weighed 1.0 grams. One reason for this variation
in seed size might be differences in how healthy
the trees are, but the scientists don’t know for
sure.
Weight of 6 Acorns
7
6
5
4
3
2
1
0
1
2
3
4
Acorn
5
6
I am going to try and grow some of the seeds I
collected with the directions Mr. DeGraan and
Ms. Sheree gave me.
What I found:
1. Different trees can have different size seeds.
2. Seeds of the same kind of tree are also
different in size.
3. The big seeds do not mean that the tree will
be big.
Thanks to:
Mr. Jeff DeGraan and Ms. Sheree Pickens of the
Washington State Department of Natural
Resources Seed Plant.
Dr. Connie Harrington of the US Forest Service,
Pacific Northwest Research Station.
I used these two books. The size of the biggest
trees in Washington came from “Champion
Trees of Washington State” by Robert Van Pelt.
The size of seeds came from the “Seeds of
Woody Plants in the United States” by the US
Forest Service. My Dad helped me make get the
weights for the seeds and make the graphs.
The End
Pictures
A new cone
Last year’s cone
A Douglas-Fir tree
with cones
Washington State Department
Natural Resources Seed Orchard
Tree seedlings growing
in a greenhouse
Tree seeds stored
in freezer (0oF)
Tree seedlings growing
outside in the nursery
Washington State Department
of Natural Resources Tree
Seedling Nursery
Tree Seeds from Washington Trees
These seeds are from the Washington State
Department of Natural Resources Seed Plant
and the Pacific Northwest Research Station.
These seeds are cleaned and have had their
wings removed to make them easier to store
and plant. The red alder seeds look blue
because they were dyed to make them easier to
see when planting.