No attempt should be made to do so until the male catkins of the wild hazel species are so entirely exhausted that no amount of shaking will release any grains of pollen.  When this condition exists, it is time to move the stored filbert branches to strong sunlight.  A quiet day should be chosen to pollinize the hazels for two reasons.  If there is a wind, it will blow away the pollen and so make the work more difficult.  A wind will also increase the danger of the hazels being fertilized by native hazel pollen which may still be circulating in the air and which the flowers may prefer to filbert pollen.

When good conditions are present, then, the hybridizer proceeds to his work.  A brush with which to transfer pollen from the vial to the pistillate blossoms is made by wrapping a little absorbent cotton around the end of a match.  The paper bag is removed from around a group of hazel blossoms, a small amount of pollen is dabbed on each blossom and the bag is immediately replaced, to remain on for two more weeks.  When the bags are finally taken off, the branches should be marked to indicate that the nuts will be hybrids.  Before receiving pollen, each pistillate blossom has, emerging from its bud tip, a few delicate red or pink spikes which are sticky enough to make pollen adhere to them.  Within a few days after receiving pollen, these spikes may dry up and turn black, a fair indication that the pollen has been effective.  If the pollen does not take hold, the spikes of the staminate blooms are sure to continue pink for a long time.  I have seen them in the middle of the summer, still blooming and waiting for pollen which would let them continue on their cycle.  This ability of hazel flowers to remain receptive for a long period allows the nut-culturist ample time to accomplish his work.  It is not so true with all members of the nut tree group, some, such as the English walnuts, being receptive for such a short period that only by very frequent examination and many applications of pollen can one be sure of making a cross.

Early in the fall, the hybrid nuts should be enclosed in a wire screen to prevent mice and squirrels from taking them before they are ripe.  Such wire screens may be used in the form of a bag and fastened around each branch.  When the husks turn brown and dry, the nuts are ripe, and ready to be gathered and planted.  Careful handling of the nuts is advisable to preserve their viability.  They should be planted in an outdoor bed which has been fully protected against the invasion of rodents.  A screen such as I described for other nut seed is satisfactory for these hybrid nuts but it need not be as large as that.  After the nuts have sprouted and the plants have grown for one season, they may be transplanted into a permanent location where they should again be well protected against mice by a trunk screen, and against rabbits by driving a stout stake deep into the ground on the south side of the tree and tying it to the tree.  This use of a stake discourages rabbits from cutting off the tree.