NORTH MANKATO — The transformation of North Mankato’s biggest park will begin in the next few weeks with the scattering of about 100 pounds of tiny seeds.

Thirteen acres of the 70-acre park on the city’s north side are being prepared as an oak savanna — the first stage in turning the wide-open and largely undeveloped land into nature-themed park with a half-dozen different habitats.

The oak piece of the oak savanna already is visible with the planting of eight bur oak trees. Another 17 are scheduled to be planted later this spring.

The savanna part is coming soon, once the broad expanse of mowed grass that now characterizes much of the park is sprayed with herbicide. The bare ground will then be planted with nearly 100 pounds of seeds from nine varieties of grasses — species such as big bluestem, silky wild rye, sideoaks grama and bottlebrush grass — and two dozen types of wildflowers.

The names of the wildflowers are as vibrant and colorful as city parks planners hope the savanna will be in coming years. There’s columbine, butterfly milkweed, prairie sage, sky blue aster, white prairie clover, pale purple coneflower, ox-eye sunflower, button blazingstar, large-flowered beardtongue, showy goldenrod, Ohio spiderwort ...

It’s just a small start of implementing a Benson Park master plan that could take 20 years to finish, but it packs some symbolic punch for North Mankato City Councilwoman Diane Norland, who heads the city’s parks advisory committee.

“It’s nice to see something grow in the face of all these financial stresses and strains,” Norland said. “The sales tax allows something to grow.”

So even as state aid reductions are forcing cuts — and probably employee layoffs — in the city’s general fund, park development is moving ahead at an unprecedented pace. The major reason is voter approval in 2006 of a half-percent sales tax to finance a new library, road projects, economic development and park improvements.

More than $600,000 has been committed to Benson Park during the next five years.

Residents also have gotten in the spirit. For several years, one anonymous donor (who City Administrator Wendell Sande says walks the park on a regular basis) has provided a trio of pin oaks each spring after receiving his tax refund. Hilltop corporations and employee groups have made several tree donations, as well, sometimes as part of Arbor Day activities.

And developer Mike Drummer has donated the 25 bur oaks that will be the hallmark of the savanna. Bur oaks can top 80 feet in height with a canopy covering a similar span, often living for 300 years or more.

Most current North Mankato residents won’t be around to see the trees reach 80 feet, but Sande expects the oak savanna — which stretches across the southern and central parts of the park — to be an attractive feature much sooner.

“You’re three to five years out to see real progress there,” he said. “It takes a number of years to build that up.”

Although the 13 acres of oaks and grasses and wildflowers will be divided by the existing trail leading from Carlson Drive to Ladybug Lake, park users won’t be restricted to the trail. The entire savanna will be open for anyone looking to get off the beaten path.

A more concentrated area of wildflowers is planned for an area north of the savanna, close to a new bay that will be dug for the lake. North of the wildflowers will be a woodland habitat, along with the part of the park that is likely to get the most intensive use.

The spot is near the larger of two planned parking lots, adjacent to the main shelter and restrooms. It will also include a picnic area and natural play areas for kids, including a small stream created to attract kids wanting to float a toy boat or maybe just looking to get wet.

Plantings and other work on the northern end will come later in the initial five-year plan, purposely delayed so that underground utilities for water, sewer and electricity can be installed.

“The infrastructure has to go in first,” Sande said. “Otherwise we’ll end up ripping up stuff that’s already done.”

A prairie is planned for the northeast corner, and large wetlands — one made from scratch on the east side and one existing marsh greatly expanded on the west side — will be among the last of the projects.

Sande, Norland and the committee involved in developing the master plan all envision a place where students on field trips learn about nature, where families can play and explore, and where people can still — with a little hiking — find some solitude.

“You’ve got a little bit of everything,” Sande said.

And while patience is still required, people who have previously been forced to picture Benson Park’s future with their mind’s eye will soon be seeing the first tangible pieces of that vision with their two peepers.

“This is wonderful,” Norland said, standing in the wide-open park, leaning into Tuesday’s gale-force winds. “The park committee is just very happy.”